Bethany observes a white crystal that is cube shaped under a microscope.



Based on this observation, Bethany thinks the crystal could be sodium chloride, or table
salt. Because the crystal has an extended structure, she knows that sodium chloride is
not a molecule. Bethany uses gray and white spheres, representing the atoms in
sodium chloride, to make a model of the crystal’s most likely structure, as shown.

a. Provide two reasons why the model accurately represents sodium chloride. Support
your reasons with evidence from the model.

b. Predict whether the melting point should be high or low based on the model.

A cylindrical weight with a mass of 3 kg is dropped onto the piston from a height of 10 m. The entropy of the gas is 1.18 J/K and the change in the entropy of the environment is -1.18 J/K.

A cylindrical weight with a mass (m) of 3 kg is dropped, that is, its initial velocity (u) is 0 m/s and travels 10 m (s). Assuming the acceleration (a) is that of gravity (9.8 m/s²). We can calculate the velocity (v) of the weight in the instant prior to the collision with the piston using the following kinematic equation.

[tex]v^{2} = u^{2} + 2as = 2 (9.8 m/s^{2} ) (10m) \\\\v = 14 m/s[/tex]

The object with a mass of 3 kg collides with the piston at 14 m/s, The kinetic energy (K) of the object at that moment is:

[tex]K = \frac{1}{2} m v^{2} = \frac{1}{2} (3kg) (14m/s)^{2} = 294 J[/tex]

The kinetic energy of the weight is completely converted into heat transferred into the gas cylinder. Thus, Q = 294 J.

Given all the process is at 250 K (T), we can calculate the change of entropy of the gas using the following expression.

[tex]\Delta S_{gas} = \frac{Q}{T} = \frac{294 J}{250K} = 1.18 J/K[/tex]

The change in the entropy of the environment, has the same value but opposite sign than the change in the entropy of the gas. Thus, [tex]\Delta S_{env} = -1.18 J/K[/tex]

A cylindrical weight with a mass of 3 kg is dropped onto the piston from a height of 10 m. The entropy of the gas is 1.18 J/K and the change in the entropy of the environment is -1.18 J/K.

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Answer:

D NO3 Nitrate is a nitrogen oxoanion formed by loss of a proton from nitric acid.

two layers of different liquids=two phases.

Because oil doesn't dissolve in water. It only floats on water.

- BRAINLIEST answerer

Answer:

Natural source of light

Explanation:

Answer:The plates are not fixed but are constantly moving atop a layer of solid and molten rock called the mantle. The Ring of Fire is a string of volcanoes and sites of seismic activity, or earthquakes, around the edges of the Pacific Ocean. ... A hotspot is a place in the middle of a tectonic plate where hot magma rises.

Explanation:

Answer:

The pulling atom is oxidized while the pulled atom is reduced. Grade 9 Chemistry

Explanation:

Answer:

You are not showing the question, but I believe the answer is cis-3,4-dimethyl-3-hexene.

Explanation:

since the substituents are on same side, it call cis. Followed by the name.

Air resistance opposes the gravity in a falling object hence the object loses speed once it reaches terminal velocity.

According to the experiment of Galileo, in the absence of air resistance, all objects that are thrown down from the same height will hit the ground at he same time due to the effect of gravity.

We know that the air resistance makes the acceleration of object to become less than the acceleration due to gravity. So, air resistance opposes the force of gravity and causes falling objects to lose speed once they reach terminal velocity.

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Answer:

The answer is D - Air resistance opposes the force of gravity and causes falling objects to lose speed once they reach terminal velocity.

Ill explain why -, for example ,

When the paper is smooth, it exposes a large surface to the air beneath it which slows its descent. Once it is crumpled, the surface which comes in contact with the air is much smaller, allowing it to fall much faster.  At first, you probably thought the book would touch the ground first since it is heavier However, once the piece of paper was crumpled, they hit the ground at the same time! Funny, since it is the same piece of paper and the book is still heavier. It all comes down to form. I hope this helped u with the test !!

Answer: O 2, 1,4

Explanation:

Answer:

from the words below underline six example of rhetorical patterns

oh so sad for ur msg

if i were science student then absolutely i will help

but i am। computer science student in management faculty so so sry

Explanation:

your answer to the chemistry question is given !

hope that helps you.

Explanation:

Oils are made up of long hydrocarbon chains which are non polar. Since water is a polar solvent oil doesn't dissolve in water well.( Polar solutes dissolve in polar solvents and non polar solutes dissolve in non polar solvents) The hydrocarbon chains are hydrophobic.

Answer:

This is a picture of it hope this helps!

The Lewis structure along with bonds for ethene (C₂H₄) is drawn below-

A Lewis Structure is a very simplified representation of the valence shell electrons in a molecule. It is used to show how the electrons are arranged around individual atoms in a molecule.

The shared pairs of electrons are drawn as lines between atoms, while lone pairs of electrons are drawn as dots next to atoms.

They also display the total number of lone pairs present in each of the atoms that constitute the molecule.

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This problem is describing the equilibrium whereby hydrofluoric acid decomposes to hydrogen and fluorine gases at 298 K whose equilibrium constant is 8.70x10⁻³, the equilibrium concentrations of all the reactants are both 1.33x10⁻³ M and asks for the initial concentration of hydrofluoric acid which turns out to be 2.86x10⁻³ M.

Then, we can write the following equilibrium expression for hydrofluoric acid once the change, [tex]x[/tex], has taken place:

[tex][HF]=[HF]_0-2x[/tex]

Now, since both products are 1.33x10⁻³ M we infer the reaction extent is also 1.33x10⁻³ M, and thus, we can calculate the equilibrium concentration of HF via the law of mass action (equilibrium expression):

[tex]8.70x10^{-3}=\frac{(1.33x10^{-3} M)^2}{[HF]} }[/tex]

[tex][HF]=\frac{(1.33x10^{-3} M)^2}{8.70x10^{-3}} }=2.03x10^{-4}M[/tex]

Finally, the initial concentration of HF is calculated as follows:

[tex][HF]_0=[HF]+2x=2.033x10^{-4}+2*(1.33x10^{-3})=2.86x10^{-3}M[/tex]

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Answer:

Atoms themselves do not have a smell. Molecules do.

Explanation:

What happens is that particular molecules bind to receptors in our nose, activating nerves, that then send signals to our brain, which we then interpret and perceive as “smells”. Different molecules bind to different receptors, which is why we can perceive a number of different smells

My classmate's statement in incorrect because plants are also composed of cells.

All living things are composed of cells. A cell is the smallest unit of living organisms. Cells obtain energy via the process of cellular respiration. During cellular respiration, glucose is broken down to yield carbon dioxide and water.

In photosynthesis, carbon dioxide and water are combined to form glucose. The two processes are opposites of each other. Plants produce their own food via photosynthesis. Since plants are composed of cells, plant cells also undergo cellular respiration therefore my classmate's statement in incorrect.

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Answer:

Meiosis produces haploid cells (gametes), which contain single chromosomes, or on-half the number of chromosomes in diploid cells. When a sperm and an egg join, the single chromosomes pair up, which results in genetic diversity in the offspring

The final temperature of the mixture in the coffee cup calorimeter is; 19.467 °C

According to the law of energy conservation:

As such; the heat transfer in the liquid water is equal to heat gained by the ice

Heat transfer by liquid water is therefore;

However, since 18g of water makes one mole

T2 = 19.467°C

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Answer:

oxygen (O2 )

Explanation:

Spontaneous processes are processes such as;  a soluble salt dissolves when it is mixed with water, iron rusts when it exposed to salty water and a match continues to burns after it is lit.

A spontaneous process is a process that occurs without external input of energy or does not require a continuous input of energy once the process has gotten underway.

Among the options the processes which are spontaneous under standard conditions of 1 atm, 298 K and 1 M are;

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The rate of a chymotrypsin-catalyzed reaction will increase by using more

enzyme in the reaction mixture.

The rate of a chemical reaction and the enzyme concentration have a direct

relationship. As concentration increases, the rate of a chemical reaction  

also increases and vice versa.

In this scenario, we were told more enzyme was used in the reaction mixture

which signifies an increase in the concentration and a corresponding

increase in the rate of reaction.

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Answer:

H3PO4 + 3KOH--------->  K3PO4 + 3H2O

Explanation

H3PO4 + KOH------------> K3PO4 + H20

when an hydrogen ion containing acid (HX) reacts with a hydroxide containing base(BOH)  they produce water and a "salt".

water can be called  dihydrogen oxide (H2O), but it can also be called

hydrogen hydroxide (HOH)...same thing.

so the phosphoric acid (H3PO4) contains 3 hydrogen ions (H), and needs 3

hydroxide ions to from 3 hydrogen hydroxides .. that is 3 waters AND A "SALT" WITH THE REMAINING SPECIES ( K AND PO4)      

so let us balance

H3PO4 + 3KOH--------->K3PO4 + 3HOH  or

H3PO4 + 3KOH--------->  K3PO4 + 3H2O

Check:

6 H on the left side, 6 H on the right side

1 P on the left side, 1 P on the right side

3 K on the left side, 3 K on the right side

7 O on the left side, 7 O on the right side

abadabaabdabadaba........that's all folks

yup it is balanced

Answer:

Direct-air capture

Explanation:

To understand the technology I'm about to explain, I'll model it to something familiar. As you know, the process of  photosynthesis is where trees and plants use sunlight, water, and carbon dioxide to create energy for themselves, and release oxygen as a byproduct. Direct- air capture is exactly like this. Its pulls in air and then through a range of similiar chemical reactions, it extracts the carbon dioxide from it while returning the rest of the air to the surrounding environment. Except, the Direct-air capture does this at a much faster rate than nature does. The direct-air capture uses a ginormous fan that pulls air in which then passes over plastic surfaces that have potassium hydroxide solutions covered over them. The potassium hydroxide solution chemically binds with the carbon dioxide molecules, removing them from the air and trapping them in the liquid solution as a carbonate salt. The carbon dioxide is then contained where it is compressed and purified and then stored for later use.

Answer:

Initial rate experiments

The simplest initial rate experiments involve measuring the time taken for some recognizable event to happen early in a reaction. This could be the time required for 5 cm3 of gas to be produced, for a small, measurable amount of precipitate to form, or for a dramatic color change to occur. Examples of these three indicators are discussed below.

The concentration of one of the components of the reaction could be changed, holding everything else constant: the concentrations of other reactants, the total volume of the solution and the temperature. The time required for the event to occur is then measured. This process is repeated for a range of concentrations of the substance of interest. A reasonably wide range of concentrations must be measured.This process could be repeated by altering a different property.

Explanation:

I don't think so if this is the answer. if not ok sorry

Answer:

The Nucleus...

it perform many activities and stores DNA in a cell.

Answer:

247 ml

Explanation:

How many mL of 0.150 M HF solution are required to produce 0.0370 moles of HF 0.150 moles/ liter = 0.150/1000 moles/ml =0.000150 moles/ml

0.000150 x ? = 0.0370 moles HF

? = 0.0370/0.000150 = 247 ml

check

247 ml = 247/1000 L = 0.247

(0.247) x (0.150) =0.370 check

Answer:

Na2S

Explanation:

hope this helps

Answer:

what's the question?

Explanation:

I'll help