Need a little help with chemistry <br> *If you don’t know, don’t put anything*

Read the summary below. Choose the answer that BEST fits into the blank to complete the summary.

777dan777 [17]

Answer:

An atom has a nucleus, made up protons and neutrons, which is surrounded by a cloud of electrons.

Explanation:

An atom is the smallest indivisible part of any element that takes place in a chemical reactions.

These are the fundamental building blocks of every element and even compounds.

There are three known subatomic particles found within an atom.
Electrons are the negatively charged particles in an atom
Protons are the positively charged particles of an atom
Neutrons do not carry any charges.

Both protons and neutrons are located within the tiny space called nucleus at the center of an atom.

Electrons moves round in orbitals at the spaces outside of the nucleus.

4 0

2 years ago

How does this splitting wedge make work easier?

nikitadnepr [17]

The ansewr is A i would guess

7 0

3 years ago

A student places three ice cubes in a beaker and allows them to partially melt. If she measures the temperature of the water in

Sonja [21]

<h2>Answers to the whole assignment:</h2>

**Check for proof photos at the bottom.**

**Answers are in bold.**

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A student places three ice cubes in a beaker and allows them to partially melt. If she measures the temperature of the water in the beaker, what will she most likely observe? Explain your answer.

She will see that the temperature of the water is 0 degrees Celsius and it stays at that temperature until all the ice cubes completely melt.

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Use the table on the right to calculate each required quantity. Record values to 3 significant digits.

First answer: 35.8 kJ

Second answer: 871 g

Third answer: Fe

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An iron sphere with a mass of 75.00 g is heated to a temperature of 385.0°C. It is then placed in a beaker containing 150.0 g H2O at 100.0°C.

First answer: 339 kJ

Second answer: 9.02 kJ

Third answer: No

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A sample of water has a mass of 100.0 g. Calculate the amount of heat required to change the sample from ice at –45.00°C to water vapor at 175.0°C. Relevant constant values are given to the right.

First answer: 325 kJ

Second answer: boiling the water

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Identify the correct description for each part labeled on the diagram.

A: ✔ heating solid

B: ✔ melting

C: ✔ heating liquid

D: ✔ boiling

E: ✔ heating gas

F: ✔ melting point

G: ✔ boiling point

Where are the particles closest together?

✔ A

<h2>Explanation:</h2>

When ice partially melts, the surrounding water remains at 0° Celsius. This is because ice melting only involves the water molecules overcoming intermolecular forces, or forces holding molecules together. The water molecules themselves aren't increasing in kinetic energy when turning into liquid. Since temperature measures kinetic energy, the temperature in this case, remains at 0°.

To find how much energy it takes to cause a phase change in a substance, you must find the number of moles, and determine whether to use ΔHvap and ΔHfus. ΔHvap is used to show how much energy is involved in evaporation and condensation, and ΔHfus is the same but used for melting and freezing. To find number of moles of a given substance, use the formula: mass of given substance divided by atomic mass. Both numbers have to use the same mass unit. Then, multiply number of moles by ΔHvap or ΔHfus to get kJ.

In a heating curve graph, the flat lines represent no change in energy, or the phase changes. The steep lines are change in energy, which are either heating or cooling. The bottom line is a heating/cooling solid. A heating/cooling solid is the coldest phase, which is why the line is at the bottom.

Here are photos of Edge to make things easier.

7 0

2 years ago

Explain why vanadium (radius=134 pm) and copper (radius=128 pm) have nearly identical atomic radii, even though the atomic numbe

Viktor [21]

<span>There are few main factors affecting the atomic radii, the outermost electrons and the protons in the nucleus and also the shielding of the internal electrons. I would speculate that the difference in radii is given by the electron clouds since the electrons difference in these two elements is in the d orbital and both has at least 1 electron in the 4s (this 4s electron is the outermost electron in all the transition metals of this period). The atomic radio will be mostly dependent of these 4s electrons than in the d electrons. Besides that, you can see that increasing the atomic number will increase the number of protons in the nucleus decreasing the ratio of the atoms along a period. The Cu is an exception and will accommodate one of the 4s electrons in the p orbital.

</span><span>Regarding the density you can find the density of Cu = 8.96g/cm3 and vanadium = 6.0g/cm3. This also correlates with the idea that if these two atoms have similar volume and one has more mass (more protons; density is the relationship between m/V), then a bigger mass for a similar volume will result in a bigger density.</span>

7 0

3 years ago

Balance the following reaction in KOH (under basic conditions). What are the coefficients in for C3H8O2 and KMnO4 in the balance

GrogVix [38]

Answer:

Coefficient of $C_3H_8O_2=3$