A. The initial mass of the sample is 6.35
B. The time taken for 0.3 mg of the sample to remain is 66 days
A. Determination of the initial mass of the sample
We'll begin by calculating the number of half-lives that has elapsedHalf-life (t½) = 15 days
Time (t) = 10 days
Number of half-lives (n) =?n = t / t½
n = 10 / 15
n = ⅔Finally, we shall determine the initial mass of the sample.Number of half-lives (n) = ⅔
Amount remaining (N) = 4 mg
Initial amount (N₀) =?[tex]N_0 = N \times {2}^{n} \\ N_0 = 4 \times {2}^{2 \div 3} \\ N_0 = 6.35 \: mg[/tex]
Therefore, the initial mass of the sample is 6.35 mg
B. Determination of the time
We'll begin by calculating the number of half-lives that has elapsedAmount remaining (N) = 0.3 mg
Initial amount (N₀) = 6.35 mg
Number of half-lives (n) =?[tex]{2}^{n} = \frac{N_0}{N} \\ \\ {2}^{n} = \frac{6.35}{0.3} \\ \\ {2}^{n} = 21.167 \\ take \: the \: log \: of \: both \: side \\ log \: {2}^{n} = log \: 21.167 \\ nlog2 = log \: 21.167 \\ divide \: both \: side \: by \: log2 \\ \\ n = \frac{log \: 21.167}{log2} \\ \\ n = 4.4[/tex]
Finally, we shall determine the timeNumber of half-lives (n) = 4.4
Half-life (t½) = 15 days
Time(t) =?t = n × t½
t = 4.4 × 15
t = 66 daysTherefore, it will take 66 days for 0.3 mg of the sample to remain.
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cobalt iii percarbonate as a formula
Answer:
Co2(CO3)3
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bonding and kinetic energy quick check
1. The internal energy within a system associated with the motion of particles and that can be added to a substance is called (1 point)
o temperature
O kinetic energy
O thermal energy
O electrostatic forces
2. which statement describes the effect of adding more energy to a system, assuming a phase change does not occur?
0 the particles within the system will have greater motion and the temperature will increase
0 the particles within the system will have greater motion and the temperature will be grace
0 particles within the system will have less motion and the temperature will increase
0 the particles within the system will have less motion and the temperature will decrease
3. which statement correctly describes how a tractions that holds particles break
0 attractions occur due to gravitational forces when particles move fast enough these forces can no longer keep particles together
0 attractions due to Electrostatic forces when particles move fast enough these forces can no longer keep particles together
0 attractions due to electrostatic forces when particles have low enough energy these forces can no longer keep particles together
0 attractions occurred due to gravitational forces when particles have low enough energy these forces can no longer keep particles together
4. Which statement explains why a rubber band analogy is not a perfect comprehension for Bonds in a substance when considering phases change
0 for a phase change from solid to liquid the bonds do not break completely and particles can still slide past each other
0 for a phase change from liquid to gas the bonds do not break completely the particles can still slide past each other
0 for a phase change from liquid to gas the bonds break completely and of particles can independently of each other
0 phase change from solid to liquid the bond breaks completely particles can move independently of each other
5.the boiling point of benzene is 80°C. which pair of samples will have the same average kinetic energy of benzene molecules?
0 two samples of gaseous benzene, at 80°C and the other 90°C
0 two samples of liquid benzene, one at 70°C and the other at 80°
0 a sample of liquid benzene at 70°C and a sample of gaseous benzene at 90°C
0 a sample of liquid benzene at 80°C and a sample of gaseous benzene at 80°celectric
When energy is added to a system during phase change, the particles move faster.
When a substance is heated, the internal energy within a system associated with the motion of particles and that can be added to a substance is called thermal energy.
During a phase change, when more energy is added to the system, the particles within the system will have greater motion and the temperature will increase.
The attractions that hold molecules together are electrostatic forces. The correct statement about the attractions that hold particles is that attractions between particles break when attractions due to Electrostatic forces when particles move fast enough these forces can no longer keep particles together.
Rubber band is not a perfect comprehension for Bonds in a substance when considering phases change because for a phase change from liquid to gas the bonds do not break completely the particles can still slide past each other.
The pair of samples that will have the same average kinetic energy of benzene molecules is a sample of liquid benzene at 80°C and a sample of gaseous benzene at 80°C.
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what class of small objects have orbits completely between the gas giants, occasionally crossing their paths?
The class of small objects with orbits completely between the gas giants is centaurs.
Centaurs are a class of small tiny bodies that circles the Sun amid Jupiter as well as the Neptune, crossing the orbits of one or more of the giant planets. It has a semi-major axis, also known as perihelion, between that the outer planets.
Centaurs' orbits are often unstable since they have crossed the orbits of more than one of the gas giant planets. They are known to have the properties of asteroids and comets.
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18 You are studying the boiling points of liquids with some fellow students You have two liquids of different molecular weights, and you test each of them twiceYou find that the one with a lower molecular weight also has a lower boiling point would like to be more confident with the patter you are noticing What are two possible next steps? In one to two sentencesgive specific, different examples of how the experiment could be extended assessed or improved
Answer:
The edge of boiling over of the substance relies upon the strength of holding between the particles, unequivocally the intermolecular powers between the atoms. The intermolecular powers that exist between the particles relies upon the idea of the atoms like extremity, sub-atomic weight, design of the atom, and so forth In testing the edge of boiling over of the two given fluids, the expansion in edge of boiling over can be noticed for the compound with higher limit. This demonstrates that there is lower intermolecular power in the compound with lower atomic weight.
Explanation:
Hope this helps
The strength of holding between the particles, namely the intermolecular forces between the atoms, determines the substance's edge of boiling over. The intermolecular forces between the particles depend on concepts related to atoms, such as extremities, sub-atomic weight, atom design, and so on.
What is an atom ?Each atom is made up of a nucleus and one or more electrons that are linked to it. One or more protons and a significant number of neutrons make up the nucleus. Only the most prevalent type of hydrogen is neutron-free. Atoms that are neutral or ionized make up every solid, liquid, gas, and form of plasma.
But when it comes to the name atom, we must travel back to 400 B.C. ancient Greece. The Greek word atomos, which meaning "uncuttable," was proposed by Democritus, a renowned philosopher. In the end, all matter could be reduced to distinct, tiny particles, or atomos, he said.
When the two supplied fluids' edges of boiling over are tested, the compound with the greater limit exhibits an expansion in the edge of boiling over. This illustrates that the compound with a lower atomic weight has a lower intermolecular power.
Thus,The intermolecular forces between the particles depend on concepts related to atoms.
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The graph below shows the solute concentration inside a paramecium over time. What is happening at the time indicated by the pointer?
Water is moving rapidly into the paramecium by osmosis.
Water is moving rapidly out of the paramecium as the contractile vacuole contracts.
The paramecium is having a meal.
Solutes from the surrounding water are diffusing through the cell membrane, causing the solute concentration inside the paramecium to rise.
The pointer indicated the point at which water is moving rapidly out of the paramecium as the contractile vacuole contracts.
The pointer specifically indicates where the water solute concentration dropped. In order for the solute concentration of the water to drop, more water would have to be added.This means that water from the paramecium moves into the surrounding water as the contractile vacuole contracts. Consequently, the solute concentration of the surrounding solution decreases. When water moves from the solution into the paramecium, the solute concentration increases and this forms a continuous cycle in the graph.More on water movement by osmosis can be found here: https://brainly.com/question/21395644?referrer=searchResults
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Angle I in the picture below is the angle of...
Select one:
a. refraction.
b. inversion.
c. reflection.
d. incidence.
Angle I in the picture above is the angle of incidence
The angle I and shown can rightly be called the angle of reflection.
According to the laws of reflection, the incident ray, the reflected ray and the normal all lie on the same plane. This gives us the idea that when two angles lie on the same plane as the normal, it may be a case of reflection.On the basis of what has been said above, the angle I and shown can rightly be called the angle of reflection.Finally, from the image, we can clearly see that angle I is the angle of reflection.
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How many mL of 0.100 M NaCl would be required to make a 0.0365 M solution of NaCl when diluted to 150.0 mL with water?
Answer:
54.75 mL
Explanation:
First calculate the number of moles of NaCl in the 150mL solution of NaCl
0.0365 moles should be present on 1000cm3 or 1dm3 of water.
1L = 1 dm3
1 mL = 1 / 1000 dm3
150 mL = 150/1000 dm3 = 0.15 dm3
If x moles are present in 0.15 dm3,
x/ 0.15 = 0.0365
We get x= 0.0365 × 0.15 mol
Now x amount of moles should be taken from the initial 0.100 M NaCl solution
So 0.1 moldm-3 = 0.0365× 0.15 mol / V
we get V = 0.05475 dm3
V= 0.05475 L
V= 54.75 mL
Draw the alkyne formed when 1,1‑dichloro‑3‑methylbutane is treated with an excess of a strong base such as sodium amide. Omit byproducts. (give the neutralized alkyne product, not the acetylide salt. ).
This problem is asking for the major alkyne product that is formed when 1,1‑dichloro‑3‑methylbutane reacts with sodium amide (NaNH₂) ignoring any byproduct.
Thus, we can firstly say that such reaction of an alkyl halide with a strong base such as sodium amide is able to remove the halogen-based substituents and hence form insaturations in the form of double or triple bonds depending on the degree of substitution.
For instance, if one halogen substituent, then an alkene will be formed; but if two, then an alkyne (like this problem).
In such a way, as shown on the attached figure, the product will be 3-methylbutyne due to the loss of two chlorine substituents.
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https://brainly.com/question/9620187https://brainly.com/question/14282000An atom of sodium has 11 electrons. Make a sketch of a sodium atom, showing how many electrons it has at each energy level. Infer how reactive sodium atoms are.
SOMEONE HELP ME PLEASE :(. I DONT GET IT :(
if your going down a hill what type of energy are you making?
Answer:
Gravitational potential energy - into Kinetic energy
Explanation:
In which process do particles move closer together but remain in motion?
А condensation
B
diffusion
с
evaporation
D
freezing
Answer: c
Explanation: the particles stay together but has some gain more heat they break apart.
How many grams of acetic acid are present in 250g of vinegar that contains 5.00% acetic acid?
The body also loses heat by the evaporation of sweat. How is a tea kettle boiling similar to the evaporation of sweat from the body?
Well they both leat sweat out, so they steam.
According to coulomb's law, in which ionic compound are the attractive forces the strongest?.
Answer:
A cation with a 2+ charge will make a stronger ionic bond than a cation with a 1+ charge. A larger ion makes a weaker ionic bond because of the greater distance between its electrons and the nucleus of the oppositely charged ion.
Which is the stereochemical relationship between this pair of molecules?.
Answer:
enantiomers
Explanation:
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What causes the electrons to move and form static electricty?
contact between two substances
friction
Moist air
Answer:
Static electricity is the result of an imbalance between negative and positive charges in an object. ... When two materials are in contact, electrons may move from one material to the other, which leaves an excess of positive charge on one material, and an equal negative charge on the other.
Answer: 1) Contact between two substances.
Explanation:
#1 When fuel is running through pipes, there is a lot of contact between the fuel and the pipe.
To avoid explosions, fuel trucks have a metal chain that hangs to the ground to discharge the static. When a jet plane is being fueled up, it is first connected to a metal spike that is sunk down into the ground.#2 Before, people thought that Static at first was caused by friction, meaning the rubbing (of an object, pause) had something to do with static.
People later on noticed that fuel trucks and jet planes were being filled with fuel.A large static charge built up from the fuel running through the pipes when fuel trucks and jet planes were being filled with fuel.End note: Your welcome. My apologies if I was late, I was trying to find the answer to this question, too, until I got all this information while taking notes from my Physical Science lesson.
Nitrogen will ____ valence electrons when forming an ionic bond.
When unbalanced forces act on an object that is in motion, the object can:
A. change speed, direction, or both.
B. only change direction.
C. only slow down.
D. only speed up.
Answer:
A. change speed, direction, or both
Explanation:
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Will the things dissolve by themselves over time?
When a substance dissolves, it looks like it disappears. But in fact it has just mixed with the water to make a transparent (see-through) liquid called a solution. A solution has two parts. The solute is the solid that gets dissolved.
Answer:
it really depends what they are
Explanation:
Which statement is always true when nuclear fusion occurs?.
Answer:
The combined number of protons and neutrons remains constant.
Explanation:
= )
I made a really helpful study set for this assignment on Quizlet. Feel free to visit the following if you need help with the rest of this assignment. Thanks and good luck!
Quizlet - "Physical Science - 5.4 Modeling Fusion and Fission Quick Check"
h t t p s : / / q u i z l e t . c o m / 7 3 7 5 5 3 6 8 0 / p h y s i c a l - s c i e n c e - 5 4 - m o d e l i n g - f u s i o n - a n d - f i s s i o n - q u i c k - c h e c k - f l a s h - c a r d s / ? n e w
Which statement best describes the effect of radioactive decay on a nucleus?.
When radioactive decay occurs, the original nucleus splits into daughter nuclei and the resulting nucleus is more stable than the original nucleus. The nucleus can be of a different element than the original.
Unstable nuclei often undergo radioactive decay. In a radioactive decay, the unstable nucleus is broken up into other nuclei. Usually, the nuclei formed during radioactive decay are smaller in mass compared to the original nucleus.
Also, the resulting nucleus is more stable than the original nucleus. The nucleus can be of a different element than the original.
Answer:
radiation travels from its source in the form of energy waves or energized particles
Explanation:
radiation is energy
What makes a hydrocarbon saturated?
Answer:
Explanation:
It's easier to answer what makes it unsaturated.
H - C ≡ C - H
This is Acetylene. It has three shared bonds between the two carbons. That many bonds makes it unsaturated.
H H
H - C - C - H
H H
Draw lines from 1 H on top to the Carbon underneath Do the same with the other hydrogen. Make the two Hydrogens on the bottom do the same thing.
The point is that Carbon has 4 bonds. 1 bond goes to the other Carbon. The other 3 take on Hydrogen. That molecule is saturated: nothing can be added in its natural state.
Q.2. Which of the following statements is true of second ionization energies?
a) That of Al is higher than that of Mg because Mg wants to lose the second electron, so it is easier to take the second electron away
b) That of Al is higher than that of Mg because the electrons are taken from the same energy level, but the Al atom has one more proton
c) That of Al is lower than that of Mg because Mg wants to lose the second electron, so the energy change is greater
d) That of Al is lower than that of Mg because the second electron taken from Al is in a p orbital, so it is easier to remove it.
Answer:
a) That of Al is higher than that of Mg because Mg wants to lose the second electron, so it is easier to take the second electron away
Statement which is true regarding second ionization energy is that ionization energy of of Al is higher than that of Mg because Mg wants to lose the second electron, so it is easier to take the second electron away.
What is ionization energy?Ionization energy is defined as the minimum amount of energy required to remove an electron which is loosely held in the outermost shell to form an isolated gaseous atom,ion or molecule.
It has a positive value for neutral atoms indicating that the ionization process is an endothermic process . The closer the outermost shell electrons are to the nucleus of an atom higher is it's ionization energy.It is expressed in electron volts or joules.
Ionization energy increases across period as more energy is required to remove electron from an atom as it is closely held along a period while it is decreasing down the group as on going the group the inter-nuclear distance increases and as a result less energy is required to remove an electron.
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under which conditions do you expect helium gas to deviate most from ideal behavior?
Answer:
Explanation:
[2-0] NC Special Operation
[2] Supervisor
[2-1] Emergency Response
[2-2] Juggernaut
[2-3] Commander
[2-4] Division Director
which professional most likely uses x-ray technology a financial analyst or a dentist
Answer:
A dentist
Explanation:
Hope this helps
Electrical Bonding and Kinetic Energy Quick Check
2. Which statement describes the effect of adding more energy to a system, assuming a phase change does not occur?(1 point)
A. The particles within the system will have greater motion, and the temperature will decrease.
B. The particles within the system will have less motion, and the temperature will increase.
C. The particles within the system will have less motion, and the temperature will decrease.
D. The particles within the system will have greater motion, and the temperature will increase
3. Which statement correctly describes how attractions that hold particles break?(1 point)
A. Attractions occur due to gravitational forces. When particles have low enough energy, these forces can no longer keep particles together.
B. Attractions occur due to electrostatic forces. When particles have low enough energy, these forces can no longer keep particles together.
C. Attractions occur due to electrostatic forces. When particles move fast enough, these forces can no longer keep particles together.
D. Attractions occur due to gravitational forces. When particles move fast enough, these forces can no longer keep particles together.
4. Which statement explains why a rubber band analogy is not a perfect comparison for bonds in a substance when considering phase changes?(1 point)
A. For a phase change from solid to liquid, the bonds break completely and particles can move independently of each other.
B. For a phase change from solid to liquid, the bonds do not break completely and particles can still slide past each other.
C. For a phase change from liquid to gas, the bonds do not break completely and particles can still slide past each other.
D. For a phase change from liquid to gas, the bonds break completely and particles can move independently of each other.
5. The boiling point of benzene is 80ºC. Which pair of samples will have the same average kinetic energy as benzene molecules?(1 point)
A. a sample of liquid benzene at 70ºC and a sample of gaseous benzene at 90ºC
B. two samples of liquid benzene, one at 70ºC and the other at 80ºC
C. two samples of gaseous benzene, one at 80ºC and the other at 90ºC
D. a sample of liquid benzene at 80ºC and a sample of gaseous benzene at 80ºC
When particles move fast enough, these forces can no longer keep particles together.
Recall that the particles of a substance are in constant random motion. Hence, when more energy is added to the system, the particles within the system will have greater motion, and the temperature will increase.
The forces that keep molecules together in a particular state of matter are electrostatic forces. When particles move fast enough, these forces can no longer keep particles together.
It is common to use the analogy of an elastic material to represent the bonding between atoms in molecules. However, this analogy is not apt in a phase change because, for a phase change from liquid to gas, the bonds break completely and particles can move independently of each other.
We know that the average kinetic energy of the molecules of a substance depends on the temperature of the body. Therefore, a sample of liquid benzene at 80ºC and a sample of gaseous benzene at 80ºC will have the same average kinetic energy as benzene molecules.
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Chemical properties of water for class 8
Answer:
pH value is 7neither acidic nor basecan be found in all 3 state (ie. liquid, solid and gas {vapour})it's excellent solventMany plant cells have chloroplasts. Which process occurs in chloroplasts?
photosynthesis
respiration
food storage
reproduction
Answer:
photosynthesis
Explanation:
chloroplasts store sugar which is needed for photosynthesis
8. Why are we focusing on high levels of ozone in the troposphere in this lab while in Lab 2 (Stratospheric Ozone) we focused on low concentrations of ozone in the stratosphere?
Answer:
f4
Explanation:
your welcome.