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Answer:

1. linear (A)

2. trigonal-planar (C)

3. tetrahedral (B)

4. linear (A)

Explanation:

Just did it on Edge 2020

The shape of a molecule can be predicted from the number of electron pairs that surround the central atom in the molecule.

The Valence Shell Electron Pair repulsion theory gives us a basis for predicting the shape of molecules. The shape of a molecule can be predicted from the number of electron pairs that surround the central atom in the molecule.

In the image shown, We can see that in HCN , carbon is the central atom and is surrounded by two atoms and no lone pairs. Since there are two electron domains around the central atom, the molecule is linear.

In the second structure, BH3 has boron as its central atom. Three electron domains surround the central atom hence the molecule is trigonal planar.

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Answer:

Molecular Mass

Explanation:

It's asking for the numerical quantity. That quantity would be the Molecular Mass. Take the sample mass and divide it by the molecular mass to get the number of moles.

(14g N * 2) + (1g H *4) = 32g / mol of N2H4

To get # of moles, divide the sample mass by the molecular mass

25g / 32g = 0.78125 moles

Explanation:

Mixtures can be separated using a variety of techniques. Chromatography involves solvent separation on a solid medium. Distillation takes advantage of differences in boiling points. Evaporation removes a liquid from a solution to leave a solid material.

Answer:

it blows up very lighty

Explanation:

Answer: Conduction

Explanation:

Answer:the answer is a chemical change, because a gas was produced

Explanation:  yeast is a chemical

Answer:

The answer is C.

"Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions."

Explanation:

Answer:

6. 53 is the answer. Hope this helps:)

The number of d electrons that an atom of atomic number 53 possess are 20. Thus, the correct option for this question is 5.

An atomic number may be defined as the number of protons in the nucleus of an atom that significantly represents the characteristic of a chemical element and determines its specific place in the modern periodic table.

According to the modern periodic table, an element that has an atomic number of 53 is known as Iodine. Its electronic configuration is [tex]1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^1^0, 4p^6, 5s^2, 4d^1^0, 5p^5[/tex]. Thus, according to this electronic configuration, the total number of d electrons are [tex]3d^1^0 and 4d^1^0[/tex].

Therefore, the number of d electrons that an atom of atomic number 53 possess are 20. Thus, the correct option for this question is 5.

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Answer:

B.  thermal conductivity

Explanation:

They physical property being tested during the fourth step is the thermal conductivity of the materials.

Thermal conductivity is the ability of a body to transmit heat energy from one place to another.

Answer:

2

Explanation:

thats the answer.have good day

Answer:

721.9 grams

I hope this helps!

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question

mass = 21.7 kg = 21700 g

volume = 5.78 cm³

We have

[tex]density = \frac{21700}{5.78} \\ = 3754.3252...[/tex]

We have the final answer as

Hope this helps you

Answer:

A, True

Explanation:

Answer:the positive ionic radius is smaller than the neutral atomic radius

Explanation:

Answer:The positive ionic radius is smaller than the neutral atomic radius.

Explanation: just took the test

Answer:

B.) The sound waves are reflected.

Explanation:

On edge,

i also answered so the other person could get the brainliest

Answer:

b

Explanation:

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\[/tex]

From the question

mass = 16 g

volume = 512 cm³

We have

[tex]density = \frac{16}{512} = \frac{1}{32} \\ = 0.03125[/tex]

We have the final answer as

Hope this helps you

The question is incomplete, the complete question is;

All surfaces have texture, which means it affects how things move over it. When it takes a long time for friction to slow down and object, what is MOST LIKELY true about the surface the object is moving on? (A) The surface is dry (B) The surface is rough (C) The surface is uneven (D) The surface is smooth

Answer:

(D) The surface is smooth

Explanation:

Friction exists because of relative motion between two surfaces in contact with each other. However the magnitude of friction depends on how rough or smooth the surface is.

For smooth surfaces, there is little or no resistance to motion as objects move over the surface. Hence objects take a longer time to slow down on a smooth surface due to very little friction.

On a rough surface, objects tend to slow down relatively quickly. Hence, less resistance to motion on a smooth surface makes an object to take a longer time to slow down on a smooth surface than on a rough surface.

Answer: D

Explanation: Because if the surface is smooth it causes it to be more even for it to be able to cause Friction

if you find this helpful, Your welcome, if not, sorry.

Answer:

The heat is transferred from your hand to the ice, this is because, as we know, heat gets transferred from a hot object to a colder object.

In this case, our hand is clearly hotter than the ice cube.

Therefore, the heat is transferred from your hand to the ice cube.

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Answer:

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

[tex]volume = \frac{mass}{density} \\ [/tex]

From the question.

density = 0.017 g/mL

mass = 4 g

We have

[tex]volume = \frac{4}{0.017} \\ = 235.2941176...[/tex]

We have the final answer as

Hope this helps you

Explanation:

The lungs pump oxygen in and carbon dioxide out, which goes through the blood stream to help with the cell's energy needs.

Nutrients pass through the blood stream as well. The nutrients start with the digestive system (mouth, esophagus, stomach, small intestine) before going into the blood stream. The nutrients are building blocks to help make new cells when old ones die off.

When those cells die off, the body sheds them like dead skin, but internal dead cells are passed off as waste. This waste and other byproducts the body doesn't need passes through the blood stream as well.

In short, the blood stream is basically the highway to help get desired materials (eg: oxygen and nutrients) and get rid of waste (eg: carbon dioxide and other unwanted byproducts or dead cell material)

So that's why the answer includes A, B and C.

Answer:

13.5 moles of Ne

Explanation:

1 mole of any gas contains  6.02 x 10²³ atoms of gas

6.02 x 10²³ atoms of neon is equal to 1 mole of neon .

8.15 x 10²⁴ atoms of neon is equal to  1 x 8.15 x 10²⁴ / 6.02 x 10²³ moles

= 8.15 x 10²⁴ / 6.02 x 10²³ mole o neon

= 13.5 moles of Ne .

Answer:

Oxygen has an atomic number of 8 , and the mass number of an atom is the sum of its atomic number plus its neutron number. We got the mass as 16 units, and so it'll have 16−8=8 neutrons.

Explanation:

Explanation:

when water is in liquid form and the temperature DROPS it becomes solid ice the process is melting , freezing and evaporation this goes in a circle

Answer:

0.000037 cm is 370 nanometers

Explanation:

Answer:

helium

Explanation:

because there are no electrons screening it from the nucleus

Answer:

See Below.

Explanation:

This is a conversion problem:

Using the molar mass of Gold (given in a periodic table) which is 196.97g/mol

you have

[tex](3.60*10^-5 g) *\frac{1moles}{196.97g}[/tex]

you always arrange the equation in a way to cancel whatever you don't want (grams) and leave what you do want (moles). Here grams cancel (top and bottom), so you're left with:

[tex]\frac{(3.60*10^-5 g) *(1)}{196.97} = 1.83*10^-7[/tex] moles of Gold

Answer:

average speed around 9.1 meters/second

Explanation:

400 divided by 43.9

Answer:

Explanation:

Answer:

Explain that unlike sound, light waves travel fastest through a vacuum and air, and slower through other materials such as glass or water.

Explanation:

Hope this helped.

Answer:

empty space

Explanation: