Answer:
93.75
Explanation:
In first half life 750×1/2 will remain
In second one half from that remained at the end of first half life will remain
That is 1/2 × 750×1/2
likewise at the end of 3rd half life 1/2 × 1/2 ×750×1/2 remains
at the end of 4th half life 1/2 × 1/2 × 1/2 ×750×1/2 remains
1/2 × 1/2 × 1/2 ×750×1/2 = 93.75 remains.
You can also use the equation
Remainder = X × 1/2^n .
This saves time
n= no. of half lives
X= initial amount
so in this case 1/2^4 × 750 = 93.75
Please help I’m soo confused what do you think might account for these similar properties? Explain
Answer:
i wonder...................
Explanation:
In a star, nuclear fusion occurs in the
A. core
B. radiative zone
C. photosphere
D. corona
Answer:
A. Core
Explanation:
The collisions which occur between the hydrogen atoms starts to heat the gas in the cloud. Once the temperature reaches 15,000,000 degrees Celsius, nuclear fusion takes place in the center, or core, of the cloud. The tremendous heat given off by the nuclear fusion process causes the gas to glow creating a protostar.
In a star, nuclear fusion which is a type of nuclear reaction occurs in the core.
What are nuclear reactions?There are two types of nuclear reactions which are nuclear fusion and nuclear fission .They involve the combination and disintegration of the element's nucleus respectively.
In nuclear fission, the nucleus of the atom is bombarded with electrons of low energy which splits the nucleus in to two parts .Large amount of energy is released in the process.It is used in nuclear power reactors as it produces large amount of energy.
In nuclear fusion,on the other hand, is a reaction which occurs when two or more atoms combine to form a heavy nucleus.Large amount of energy is released in the process which is greater than that of the energy which is released in nuclear fission process.
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List the 4 main components of air in their molecular form.
Answer:
Air is made up of 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and other gases in meager amounts.
A student has a sample of ocean water that they take to science class. what steps could be taken to determine to classify the ocean water as a suspension, solution, element, or compound?
A) Examine the pH of the sample. If the pH is exactly neutral, it is a pure substance that is a compound.
B) Evaporate the water. If salt is left behind, the sample is a mixture that can be defined as a solution.
C) Let the sample settle. If the salt settles to the bottom, it is a mixture that is classified as a solution.
D) Observe the diffraction of light as it moved through the sample. If light does not scatter, it is a pure substance that is elemental.
Answer:
A or D because B and C dont make sense
Write the net ionic equation for the reaction that occurs, if any, when gold is placed in a solution of hydrobromic acid
Answer:
ionic salt MX2
Explanation:
Atoms from an element in group IIA are allowed to react with atoms from an element in group VIIA. What type of compound is likely to form
elements from IIA are alkali earth metals (M) and need to lose
2 e^1- to become stable as M^2+
elements from VIIA ar halogens (X) and need to gain 1 e^1-
to become stable so one M^2+ combines with 2 X^1- to make
an ionic salt MX2
Which body systems are responsible to transport materials around and out of the body?
Answer:
Circulatory System
Explanation:
How many atoms of lithium are there in 18.2mg of lithium? Dimensional analysis only!
Answer:7.25
Explanation:
This is because 18.2 - 7.2 = 11 +7.2 = 18.2
Convection currents are one force driving plate tectonics. What other force plays a major role?
Heat transfer
Gravity
Radioactive decay
Fossil formation
Answer:
Gravity
Explanation:
Gravity was founded by famous physician Sir Izak Newton.The gravity is a phenomenon by which every object in the universe attracts eachotherNewton discovered gravity by the falling apple from tree.The following factors contribute to plate tectonics: The Mantle's Convection. Mountain push gravitational force at the spreading ridges, Block pull gravitational force in subduction zones. Hence, option B is correct.
What is gravitational force ?The gravitational force, which is what pushes mass-containing objects toward one another. We frequently consider the pull of gravity from the Earth. Your body is kept on the ground by this force. However, all mass-bearing objects are pulled toward one another by gravity.
Population growth and changes in people's wants and activities are the main causes behind this. Changes in the overall levels of output and consumption are caused by these main movers.
The driving forces put strain on the environment through these modifications to production and consumption. In the direction of motion, gravity produces an active driving force.
Thus, option B is correct.
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Distinguish between the first, second, and third ionization energies of an atom. b. How do the values of successive ionization energies compare
Answer:
The third ionization energy is the energy it takes to remove an electron from a 2+ ion. (That means that the atom has already lost two electrons, you are now removing the third.) And 2nd ionization energy is higher than 1st ionization energy, 3rd is higher than 2nd, and so forth.
hope it is helpful :)
how long does it take for chlorine to evaporate from water?
Answer:
1 to 5 days
Explanation:
29.0 argon combine completely with 4.30 g of Sulfur.
Calculate the percent compositions of the compounds that are formed from the reaction
Answer:
33.3
Explanation:
if we were to add 29.0 of argon and 4.30 of sulfur and that would come out 33.3.
What is called exothermic
An exothermic process is one that gives off heat.
Explanation:
This heat is transferred to the surroundings. An endothermic process is one in which heat has to be supplied to the system from the surroundings.
Please help! Giving 20 points!
Question: How can NASA scientists use Newton's third law of motion to plan for a space vehicle landing on a meteor? Make a claim. Support your claim with evidence from the article. Then, explain why the evidence supports your claim.
Article: https://newsela.com/read/lib-newton-third-law/id/54749/
Answer:
Explanation:
NASA uses rockets to launch astronauts and supplies to the International Space Station. Launching a rocket relies on Newton's Third Law of Motion. A rocket engine produces thrust through action and reaction. The engine produces hot exhaust gases which flow out of the back of the engine
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When a person goes on a diet, do they really want to lose weight or mass?
Need answer asap
Answer:
Cutting calories will help you lose weight. But dieting alone can strip away muscle along with body fat. Research suggests that as much as 25 per cent of weight lost by dieters is from muscle. And that's not a good thing.
Explanation:
14 In which group are all the elements found
naturally only in compounds?
(1). 18
(3) 11
(2) 2
(4) 14
Determine the wavelength of the light absorbed when an electron in a hydrogen atom makes a transition from an orbital in which n=2n=2 to an orbital in which n=7n=7.
Answer:
The expression for the wavelength of radiation is,
λ
1
=R(
n
1
2
1
−
n
2
2
1
)
Substitute values in the above expression,
λ
1
=109677×(
2
2
1
−
4
2
1
)=109677×(
4
1
−
16
1
)=109677×(
64
12
)
λ=4.86×10
−5
cm=486×10
−9
m=486nm.
The line belongs to bluish green colour.
An iron object alloyed with cobalt rusts more quickly than a pure iron object. However, an iron object alloyed with manganese rusts less quickly than a pure iron object under the same conditions. This is true because: __________
a. cobalt is a stronger reducing agent than iron
b. iron is a stronger reducing agent than manganese
c. cobalt exhibits more metallic character than either iron or manganese in the iron-manganese alloy
Rusting is an electrochemical reaction. Iron rusts faster when alloyed with cobalt than when alloyed with manganese because, in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode
An alloy is a combination of two metals. There are various reasons for producing alloys such as greater tensile strength, corrosion resistance and improved aesthetic appearance.
When iron is alloyed with cobalt, the iron rusts faster than pure iron because iron is rendered the anode and cobalt is rendered the cathode. When the iron is alloyed with manganese, it rusts more slowly than pure iron because in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode.
Missing parts;
An iron object alloyed with cobalt rusts more quickly than a pure iron object. However, an iron object alloyed with manganese rusts less quickly than a pure iron object under the same conditions. This is true because
(1) cobalt is a stronger reducing agent than iron
(2) iron is a stronger reducing agent than manganese
(3) cobalt exhibits more metallic character than either iron or manganese
(4) in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode
(5) in the iron-cobalt alloy, cobalt is rendered the anode and iron is rendered the cathode
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A student was performing paper chromatography and let the separation continue overnight. The
A student was performing paper chromatography and let the separation continue overnight. The student wished to determine if the mixture contained a substance with an RF factor of 0.343 where:
Rf = (distance travelled by the component)/(distance travelled by the solvent)
a) What data would be affected by this error?
b) Explain the effect on the calculated Rr.
Based in the information given, the data that'll be affected by the error is the value of the solvent data.
It should be noted that the data that'll be affected based on the scenario given is the value of the solvent. When the preparation is kept overnight, there'll be an overflow of the solvent.
In such a case, it'll be difficult to get the correct distance that the solvent travelled. The effect on the calculated Rr is that the calculated Rr will be incorrect due to the error in solvent value.
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When we lower the temperature of the solvent, the rate of dissolving of the solute will....?
Answer:
Decrease
Explanation:
An increase in temperature would increase the dissolution rate and a decrease in temperature would decrease the dissolution rate
Answer:
The rate of dissolving of the solute will increase I think
Determina la molaridad de una solución de H2S, si se colocaron 37 ml del ácido en 890 ml de solución. La densidad del H2S es de 1.36 g/ml
Por definición de molaridad y densidad, la molaridad de la solución es 1.66 [tex]\frac{moles}{litros}[/tex].
La concentración molar o molaridad es una medida de la concentración de un soluto en una disolución que indica el número de moles de soluto que están disueltos en un determinado volumen.
La molaridad de una solución se calcula dividiendo los moles del soluto por el volumen de la solución:
[tex]Molaridad=\frac{numero de moles de soluto}{volumen}[/tex]
La Molaridad se expresa en las unidades [tex]\frac{moles}{litros}[/tex].
Por otro lado, la densidad es una magnitud que permite medir la cantidad de masa que hay en determinado volumen de una sustancia.
Entonces, la expresión para el cálculo de la densidad es el cociente entre la masa de un cuerpo y el volumen que ocupa:
[tex]densidad=\frac{masa}{volumen}[/tex]
En este caso, siendo H₂S el soluto, se colocaron 37 ml del ácido, siendo su densidad 1.36 [tex]\frac{g}{mL}[/tex]. Reemplazando en la definición de densidad se obtiene:
[tex]1.36\frac{g}{mL}=\frac{masa}{37 mL}[/tex]
masa= 1.36 [tex]\frac{g}{mL}[/tex]× 37 mL
masa= 50.32 g
Siendo 34 g/mol la masa molar de H₂S, es decir la cantidad de masa que una sustancia contiene en un mol, la cantidad de moles de H₂S puede ser calculada como:
[tex]numero de moles de H_{2}S= 50.32 grams\frac{1 mole}{34 grams}[/tex]
número de moles de H₂S= 1.48 moles
Siendo 890 mL=0.890 L el volumen de la solución, entonces la molaridad puede ser calculada como:
[tex]Molaridad=\frac{1.48 moles}{0.890 L}[/tex]
Molaridad= 1.66 [tex]\frac{moles}{litros}[/tex]
Finalmente, la molaridad de la solución es 1.66 [tex]\frac{moles}{litros}[/tex].
Aprende más:
https://brainly.com/question/17647411?referrer=searchResultshttps://brainly.com/question/21276846?referrer=searchResultswhich of the following best describes the relation ship between oxygen and chlorine
A. Oxygen and chlorine have the same symbols
B. Oxygen atoms have fewer protons than chlorine atoms
C. Oxygen and chlorine have the same properties
D. Oxygen atoms have twice as many protons as chlorine atoms
Answer:
B
Explanation:
The oxygen atoms have fewer protons than chlorine atoms:) hope this helps:))
According to the electronic configuration, oxygen atoms have fewer protons and electrons than chlorine atoms.
What is electronic configuration?Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
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What is an electrolysis
Answer:
Definition of Electrolysis :- Electrolysis, process by which electric current is passed through a substance to effect a chemical change. The process is carried out in an electrolytic cell, an apparatus consisting of positive and negative electrodes held apart and dipped into a solution containing positively and negatively charged ions.Explanation:
Hope this helps you dear ✌️Carry on learning !!How are traits inherited?
Please explain thoroughly
inherited traits are passed from parent to offspring according to the rules of Mendelian genetics. Most traits are not strictly determined by genes, but rather are influenced by both genes and environment
What are the word equations for the following? Please help
Calcium oxide + water
Magnesium + hydrochloric acid
Sodium hydrogen carbonate + citric acid
Iron + salt water
Calcium oxide + water = calcium hydroxide.
Magnesium + hydrochloric acid = magnesium chloride + hydrogen.
Sodium hydrogen carbonate + citric acid = Na3C6H5O7(aq)+3H2O(l)+3CO2(g)
Iron + salt water = 4Fe(OH)3 (rust)
Answer:
1. CaO + H2O _____ Ca(OH)2
Calcium oxide + Water _____ Calcium hydroxide
2. 2 HCI + MG _____ MgCl2 + H2
Magnesium + hydrochloric acid _____ Magnesium Chloride + hydrogen gas
about how many bacteria colines will grow in a agar plate with a swab of ginger oil
about 6 to 9 colines
if its from mouth if thats the case
what type of intermolecular force causes the dissolution of nacl in water?
Answer:
ion-dipole forces
Explanation:
positive sodium ion will be attracted to the slightly negative oxygen atoms in the water molecule, while the negative chloride ion is attracted to the slightly positive hydrogen atoms.
Which element has 12 protons 12 neutrons and 12 electrons
Answer:
Magnesium
Explanation:
Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column of the periodic table: all group 2 elements have the same electron configuration in the outer electron shell and a similar crystal structure.
In which container are the particles of water moving fastest? In which container are the particles moving slowest
Answer:
Particles move faster the farther they are apart, so the container with the most spread out particles.
what is the answer ??z???????
Answer:
Females
Explanation:
Hope that helps
Answer:
The answer may be no characters
If I'm right or wrong plz reply to me
What are the similarities and differences between living on Earth versus living in space?
find 5 points for each section
Answer:
Differences
• Space is everything in the universe beyond the top of Earth's atmosphere - The moon, Stars, Milky way, etc.
• In space, no one can hear you scream. This is because there is no air in space, i.e, it's vacuum.
• Earth is a planet on solar system. It is the only planet where life exists!!
• Earth is also called "blue sky" cause it has 75% water.
Similarities
•They need oxygen for survival: Man, animals in earth and space need oxygen for survival.
•Water is also need to stay alive.
•Food is very paramount to both man, animal s and organisms.
•Shelter, we all ned a place to lay our head in other to be safe.
•Air everywhere in the atmosphere.
•Water, air, food and shelter are available on earth but their availability differs in space.
•Astronaut need to bring everything one need in space with him or her from Earth. They often recycle the things they bring.
Hope it helps :)
The atmospheric conditions in earth and space is entirely different. Therefore the living in earth and space will be far different on many aspects such as adaptations, habits etc.
What are aliens?The living things that are believed to be exists in out of earth is called aliens. Some studies shows that there is a possibility to find exotic species living in space.
The study which deals with aliens is called exo-biology. The atmosphere thus, the presence gases, temperature, pressure, etc. will be different for space from that in the earth.
Hence, aliens may need not the presence of oxygen for living as well as the atmospheric conditions that maintains living in earth will not be there in space.
However, any living irrespective of earth or space need water and some kind of food to survive. Thus the presence of water in some planets opens the way to study the presence of livings there.
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