Answer:
D
Explanation:
A 2.50 g sample of zinc is heated, then placed in a calorimeter containing 65.0 g of water. Temperature of water increases from 20.00 oC to 22.50 oC. The specific heat of zinc is 0.390 J/goC. What was the initial temperature of the zinc metal sample? (final temperatures of zinc and water are the same)
Answer:
719.83°C
Explanation:
The heat that the sample of Zinc gives is equal to the heat that water is absorbing. That is:
C(Zn) * m(Zn) * ΔT(Zn) = C(H2O) * m(H2O) * ΔT(H2O)
Where:
C is specific heat (Zn: 0.390J/g°C; H2O: 4.184J/g°C)
m is mass (Zn: 2.50g; H2O: 65.0g)
ΔT (Zn: ?; H2O: (22.5°C - 20.0°C = 2.50°C)
Replacing:
0.390J/g°C * 2.50g * ΔT(Zn) = 4.184J/g°C * 65.0g * 2.50
ΔT(Zn) = 697.33°C
As final temperature of Zn is 22.50°C, initial temperature is:
Initial temperature: 697.33°C + 22.50°C
719.83°C
How large would the United States (2000 miles across) be?
Answer:
3,717,813
Im not sure, I will get back to you soon
Confirmatory test of oxygen meaning?
Answer:
Oxygen supports combustion so a good method of testing for oxygen is to take a glowing splint and place it in a sample of gas, if it re-ignites the gas is oxygen. This is a simple but effective test for oxygen.
Explanation:
PLS HELPPPPP
Calculate the mass of one water molecule.
1. 4.234 × 10−23 g/molec
2. 5.012 × 10−22 g/molec
3. 2.503 × 10−23 g/molec
4. 2.992 × 10−22 g/molec
5. 2.992 × 10−23 g/molec
6. 1.624 × 10−23 g/molec
7. 4.234 × 10−22 g/molec
Answer:
9vguvvg9uvu
Explanation:
The mass of one mole or 6.02 × 10²³ molecules of water is 18 g/mol. Then, the mass of one molecule of water is 2.99 × 10⁻²³ g/molecule.
What is Avogadro number?The number of atoms that constitutes one mole of a substance is called Avogadro number. It is equal to 6.02 × 10²³. Thus, one mole of every elements contains Avogadro number of atoms.
Similarly, one mole of a compound contains 6.02 × 10²³ number of molecules. Thus, one mole of water contains these much molecules. The mass of one mole of an element is called its atomic mass. Similarly the mass of one mole of a compound is called its molar mass.
Molar mass of water = 18 g/mol
18 g is the mass of 6.02 × 10²³ molecules of water. Hence, the mass of one molecule of water is;
= 18 g/mol/6.02 × 10²³ molecule/mol
= 2.99 × 10⁻²³ g/molecule
Therefore, the mass of one molecule of H₂O is 2.99 × 10⁻²³ g/molecule.
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5. The mass of cobalt-60 in a sample is found to have decreased from 0.800g to 0.200g in a
period of 10.5 years. From this information, calculate the half-life of cobalt-60.
Answer:
5.25yr
Explanation:
I think so
At STP there is 112L of HCl gas in a container. Read the stem and answer Q. No. 1 & 2.
1. What is the amount of gas in the container?
You have four fixed-volume containers at STP. Container A has 0.5 mol of gas in 11.2L. Container B has 2 mol of gas in 22.4 L. Container C has 1 mol of gas in 22.4L. Container D has 2 Mol gas of gas in 11.2 L. Which of the four containers have equal pressures
A and C
Is selenium tetrafluoride an ionic or covalent bond?
Answer:
Synthesis
The first reported synthesis of selenium tetrafluoride was by Paul Lebeau in 1907, who treated selenium with fluorine:[1]
Se + 2 F2 → SeF4
A synthesis involving more easily handled reagents entails the fluorination of selenium dioxide with sulfur tetrafluoride:[2]
SF4 + SeO2 → SeF4 + SO2
An intermediate in this reaction is seleninyl fluoride (SeOF2).
Other methods of preparation include fluorinating elemental selenium with chlorine trifluoride:
3 Se + 4 ClF3 → 3 SeF4 + 2 Cl2
Structure and bonding
Selenium in SeF4 has an oxidation state of +4. Its shape in the gaseous phase is similar to that of SF4, having a see-saw shape. VSEPR theory predicts a pseudo-trigonal pyramidal disposition of the five electron pairs around the selenium atom. The axial Se-F bonds are 177 pm with an F-Se-F bond angle of 169.2°. The two other fluorine atoms are attached by shorter bonds (168 pm), with an F-Se-F bond angle of 100.6°. In solution at low concentrations this monomeric structure predominates, but at higher concentrations evidence suggests weak association between SeF4 molecules leading to a distorted octahedral coordination around the selenium atom. In the solid the selenium center also has a distorted octahedral environment.
Reactions
In HF, SeF4 behaves as a weak base, weaker than sulfur tetrafluoride, SF4 (Kb= 2 X 10−2):
SeF4 + HF → SeF3+ + HF2−; (Kb = 4 X 10−4)
Ionic adducts containing the SeF3+ cation are formed with SbF5, AsF5, NbF5, TaF5, and BF3.[3] With caesium fluoride, CsF, the SeF5− anion is formed, which has a square pyramidal structure similar to the isoelectronic chlorine pentafluoride, ClF5 and bromine pentafluoride, BrF5.[4] With 1,1,3,3,5,5-hexamethylpiperidinium fluoride or 1,2-dimethylpropyltrimethylammonium fluoride, the SeF62− anion is formed. This has a distorted octahedral shape which contrasts to the regular octahedral shape of the analogous SeCl62−. [5]
Explanation:
A cylinder shaped water tank has a height of 212 ft (6461.76 cm), and is able
to hold 15,000 gallons of water (15,000,000 mL or 15,000,000 cm3). The
volume of a cylinder is expressed by the equation
V = tr^2h
Where V is the volume, r is the radius, and h is the height of the cylinder.
Express the radius (r) in terms of volume (V) and height (h), then determine
the radius of a cylinder water tank (in centimeters) that is filled to capacity.
Answer:
27.19 cm.
Explanation:
From the question given above, the following data were obtained:
Height (h) of cylinder = 6461.76 cm
Volume (V) of cylinder = 15000000 cm³
P1 (π) = 3.14
Radius (r) =.?
Thus, we can obtain the radius of the cylinder water tank by using the following formula as illustrated below:
V = πr²h
15000000 = 3.14 × r² × 6461.76
15000000 = 3.14 × 6461.76 × r²
Divide both side by 3.14 × 6461.76
r² = 15000000 / (3.14 × 6461.76)
Take the square root of both side
r = √[15000000 / (3.14 × 6461.76)]
r = 27.19 cm
Thus, the radius of the cylinder water tank is 27.19 cm.
Which factor most directly affects potential energy but not kinetic energy?
Answer: The 'mass of the object' directly affects kinetic energy
Explanation:
How much force is needed to accelerate a 56 kg skier at 3 m/s?
Answer:
168 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 56 × 3
We have the final answer as
168 NHope this helps you
Which correctly lists three characteristics that are used to describe air?
Answer: density, Omass, radiation, pressure because Radiation pressure is the mechanical pressure exerted upon any surface . Small bodies are more affected than large ones because of their lower mass relative to their surface area formed by the radiation pressure of the young stars reduces the cluster mass enough to allow rapid dispersal.
Explanation: I Hope that helped!!!
mass, pressure, density
Which issue associated with nuclear power is the biggest source of debate?
Answer:
i think it's D
Explanation:
sorry if its wrong
The issue that is associated with nuclear power is the biggest source of debate is what to do with radioactive waste. The correct option is D
What is nuclear power?Nuclear power is the power that is generated by combining or breaking nuclear atoms. There are two processes for generating nuclear power. They are nuclear fission, in which the breaking of big nuclei happens. Nuclear fusion, in which two nuclei join together to form a big nucleus.
Nuclear waste is the radiation generated from nuclear fission and fusion. This waste is very harmful to nature and animals. It can cause many deformities in humans and genetic disorders.
Nuclear waste is highly challenging, and its disposal is very hard, deep geological disposal is the only option.
Thus, the correct option is D, what to do with radioactive waste.
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Which one is NOT part of the brain?
O cerebral cortex
Frontal Lobe
cerebral palsy
hippocampus
Answer:
The awnser is cerebral palsy
Explanation:
that is a medical condition caused when there is not enough oxygen to the brain at birth
BRAINLIEST PLEASE
a motorcycle is moving along a road for a distance of 20KM. After 2 hours what is it's the average speed?
Answer:
If it took the motorcycle 2 hours to cover 20km, then the average speed is 10km per hour.
Explanation:
Speed is equal to distance over time. So 20km divided by 2 hours is 10 km per hour.
Please mark brainliest!!! Thanks.
Answer:
96.56063 km/h
Explanation:
What field(s) does a moving electron have?
ОА.
electric and gravitational fields
OB. magnetic and gravitational fields
OC. gravitational, electric, and magnetic fields
OD.
electric field only
Answer:
electric field or magnetic field both are same
Explanation:
in an electromagnet the movement of electrons in a wire creates the magnetic field.an electromagnet and the permanent magnet both the magnet have the magnetic fields that can attract the same kinds of materials.
What type of substance is gravel
Answer:
When substances do not mix thoroughly and evenly (like sand and gravel), the mixture is said to be heterogeneous. A heterogeneous mixture consists of visibly different substances. Another example of a mixture is salt dissolved in water.
Hope it helps!
two differentiate between north and south poles of magnets
Answer:
A permanent magnet has two different magnetic poles, called the north and south poles. The field lines are inside the magnet. Magnetic poles of the same charge repel each other. Thus, the north pole with another north, the south pole and with another south pole are repelled.
Explanation:
HELP ASAP I NEED HELP FAST PLEASE
Kinetic energy is often referred to the energy of
Question 1 options:
A)work
B)mass
C)motion
D)force
)
Question 2 (1 point)
Saving...
Which example has the least kinetic energy
Question 2 options:
A)a 10 kg rock rolling down a hillside at 100 m/s.
B)a 100 kg rock rolling down a hillside at 100 m/s.
C)a 1 kg rock rolling down a hillside at 1 m/s.
D)a 100 kg rock rolling down a hillside at 1 m/s.
Question 3 (1 point)
Saved
The law of conservation of energy states that
Question 3 options:
energy can be created but not destroyed.
energy can neither be created nor destroyed, only change forms.
energy can be destroyed but not created.
Question 3 (1 point)
Saved
The law of conservation of energy states that
Question 3 options:
A energy can be created but not destroyed.
B energy can neither be created nor destroyed, only change forms.
C energy can be destroyed but not created.
D energy never changes
Which is an example of an object increasing its kinetic energy
Question 4 options:
A a train stopped at the station.
B an airplane after landing on a level runway.
C a mouse running faster after spotting a cat.
D a rocket before launch.
Question 5 (1 point)
Identify when an object has a kinetic energy of zero joules.
Question 5 options:
A when an object is no longer in motion.
B when the energy has been destroyed.
C just after a ball it leaves your hand pitching a ball.
D as a pendulum swings downward.
Which is NOT an example of kinetic energy
Question 6 options:
A an elevator moving up to the 3rd floor.
B a skateboard rolling down a hill.
C an arrow after it has hit the target and is at rest.
D a skydiver as they decrease speed after opening their parachute.
1. C
2. D (I’m not entirely sure)
3.energy can neither be created nor destroyed, only change forms.
4. C
5. A
6. C
I’ve researched and tried to answer these questions correctly.
Answer:
1.c
2.a
3.created or destroyed
4.c
5.a
6.c
Explanation:
thanks me later
Normal red blood cells slide easily through narrow blood vessels. In sickle cell disease, many red blood cells change to a crescent shape like a slender moon. Crescent-shaped blood cells cause blockages in blood vessels. These blockages decrease the transport of oxygen. People with sickle cell disease often have sharp pains due to the lack of oxygen in parts of the body.
The sickle cell version of the gene that causes sickle cell disease is recessive. Suppose that two parents with no symptoms have a child with sickle cell disease. What genes did the child inherit from the parents?
A. The child must have inherited the sickle cell gene from the mother and the normal gene from the father.
B. The child must have inherited the normal gene from the mother and the sickle cell gene from the father.
C. The child must have inherited sickle cell genes from both parents.
D. The child must have inherited normal genes from both parents.
Answer:
C. The child must have inherited sickle cell genes from both parents.
Explanation:
Because of the fact that sickle cell disease is recessive, the child would have to get the gene from both parents.
Answer:
The child must have inherited sickle cell genes from both parents.
WHICH RIBBON WOULD BE CONSIDERED THE SENIOR RIBBON AND WOULD BE PLACED TO THE LEFT NEAR YOUR HEART?
SEA CRUISE RIBBON
ACADEMIC TEAM RIBBON
PARTICIPATION RIBBON
2. WHICH RIBBON WOULD BE CONSIDERED THE LEAST RIBBON AND WOULD BE PLACE TO THE FAR RIGHT OF THE RIBBON BAR?.
SEA CRUISE RIBBON
ACADEMIC TEAM RIBBON
PARTICIPATION RIBBON
3. WHICH RIBBON WOULD BE CONSIDERED THE SENIOR RIBBON?.
ORIENTATION RIBBON
MARKSMANSHIP TEAM RIBBON
LEADERSHIP TRAINING RIBBON
4. WHICH RIBBON WOULD BE CONSIDERED NEXT TO THE SENIOR RIBBON?
ORIENTATION RIBBON
MARKSMANSHIP TEAM RIBBON
LEADERSHIP TRAINING RIBBON
5. PLACE AN X BESIDE THE SENIOR RIBBON.
EXEMPLARY CONDUCT
DISTINGUISHED CADET
DISTINGUISHED UNIT
*I'm sorry they don't have a naval science subject option*
Answer:
?
Explanation:
solids are most likely amorphous solids
Answer:
what? what do you mean?
HELPPPPPP
Algae lives on the back of a spider crab. The crab blends with the shallow water of the ocean floor because of the greenish-brown color of the algae. The algae get a place to live and the crab gets camouflage. What is the name of the relationship that exists between the algae and the spider crab?
Commensalism
Competition
Mutualism
Parasitism
Answer:
it's a symbiotic mutual relationship
Explanation:
Greenish-brown algae lives on the crab's back, helping the crabs blend in with their enviroment, which makes them less noticeable to predators. the algae provided with a good place to live while the crab receives camouflage.
Answer:
Mutualism
Explanation:
Mutualism; One organism live in, on, or near another, and both gain something they need for survival. Both organisms are heled.
Which feature of a map shows the relationship between a distance on a map and that distance on Earth? key scale grid system compass rose
Answer:
Scale is the right answer
Explanation:
The scale is a sentence that relates distance on the map to distance on Earth
The scale of a map represents the relationship between the distances on the map and the actual distances on Earth.
What is map ?A map is a symbolic representation of selected features of a location, typically drawn on a flat surface. Maps present information about the world in a straightforward, visual format. They teach about the world by displaying country sizes and shapes, feature locations, and distances between locations.
The ratio of a distance on Earth to the same distance on a map is known as map scale. On maps, three types of scales are commonly used: written or verbal scales, graphic scales, and fractional scales.
The map scale is the relationship between the distance on a map and the actual distance on Earth.
Thus, The scale of a map represents the relationship between the distances on the map and the actual distances on Earth.
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explain the properties of blood that allow it to be a key piece of evidence
In acidic solution. A 70.0 mL sample of a solution containing Fe2+ requires 70.0 mL of a 0.150 M KMnO4 solution for complete reaction. What is the concentration of the Fe2+ in the original solution?
Answer:
0.75M Fe²⁺
Explanation:
First, we need to balance the redox reaction in acidic medium. Then, we can obtain moles of KMnO4 and with the reaction moles and molarity of the Fe²⁺ solution:
Redox Balance:
Fe²⁺ → Fe³⁺ + 1e⁻
5e⁻ + 8H⁺ + MnO₄⁻ → Mn²⁺ + 4H₂O
___________________________
5Fe²⁺ + 5e⁻ + 8H⁺ + MnO₄⁻ → 5Fe³⁺ + 5e⁻ + Mn²⁺ + 4H₂O
5Fe²⁺ + 8H⁺ + MnO₄⁻ → 5Fe³⁺ + Mn²⁺ + 4H₂OMoles of KMnO₄:
70.0mL = 0.0700L * (0.150mol / L) = 0.0105 moles KMnO₄
Moles and molarity Fe²⁺:
0.0105 moles KMnO₄ * (5 moles Fe²⁺ / 1mol KMnO₄) = 0.0525 moles Fe²⁺
In 70.0mL = 0.0700L:
0.0525 moles Fe²⁺ / 0.0700L =
0.75M Fe²⁺
8. Which statement correctly describes the location and charge of the electrons in an atom?
Answer:
The protons are located in the nucleus and have a positive charge
Explanation:
I need this answer ASAP! In order for conduction to transfer heat from one object to another, what must be true?
Answer:
The objects should be far apart. There must be air circulation. The objects need to be touching. Solar energy is required.
Explanation:
What is the speed of an electromagnetic wave that has a frequency of 7.8x106
Hz?
Answer:
3. x 10⁸m/s
Explanation:
Given parameters:
Frequency of wave = 7.8 x 10⁶Hz
Unknown:
Speed of the wave = ?
Solution:
All electromagnetic radiation has a speed of 3. x 10⁸m/s in free space.
No matter the frequency and wavelength, they all have the same speed which is the same as the speed of light.
The speed of electromagnetic wave that has a frequency of [tex]7.8 * 10^{6}[/tex] Hz is [tex]3 * 10^{8}[/tex] m/s.
Electromagnetic waves:
Higher-frequency electromagnetic waves have less energy. All electromagnetic waves travel across space at the speed of light which is [tex]3 * 10^{8}[/tex] m/s.
As we know that,
Speed=frequency x wavelength,
It follows that the wavelength will also not change. So the direction, speed, frequency and wavelength of any electromagnetic wave are constant and these properties will not change after emission from a source.
Thus, speed of an electromagnetic wave is fixed and does not change on varying frequencies which is [tex]3 * 10^{8}[/tex] m/s.
OR
The waves travel at the same speed, but the observed frequency depends on any relative motion between the observer and source.
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How is the movement of electrons between energy levels like climbing a ladder?
When iron reacts with oxygen, it forms iron oxide, or rust.
Answer:
rust
Explanation: