What does the bottom number within each box of the periodic table refer to? How can it be used to determine the number of neutrons inside an element?

Answer:

Atomic Number

Explanation:

The number below the symbol is the atomic number and this reflects the number of protons in the nucleus of each element's atom. Every element has a unique atomic number.

Which of these are elements? Choose the two correct answers.

A.
sugar

B.
carbon

C.
oxygen

D.
protein

Based on the cell theory, which of the following is true?

All living and nonliving things are made of cells.
All cells are too small to be seen with the naked eye.
Small organisms have smaller cells than large organisms.
Large organisms have more cells than small organisms.

BRAINLIEST - ANSWER QUICKLY
Question 1 (1 point)

Saved

Which of the following is the BEST evidence of a chemical change?


Question 1 options:


Two solids forming a mixture.



Two liquids forming layers instead of mixing.



Two liquids mixing to produce a precipitate.



Two liquids mixing to blend their colors.


Question 2 (1 point)

Saved

Which of the following is NOT an example of a physical change?


Question 2 options:


A metal rod bends.



A metal rod is cut into two metal rods.



A metal rod dissolves in acid.



A metal rod is stretched longer.


Question 3 (1 point)

Saved

In a cup of liquid water, when would the water molecules stop moving?


Question 3 options:


The molecules would stop moving if the liquid water in the cup became still.



The molecules would not stop moving in the cup of liquid water.



The molecules would stop moving if the liquid water in the cup became a solid.



The molecules would stop moving if the liquid water in the cup became a gas.


Question 4 (1 point)

Saved

In which state(s) of matter could a substance have thermal energy?


Question 4 options:


Only liquids and gases



Only liquids and solids



Only liquids



Liquids, solids, and gases


Question 5 (1 point)

Saved

Which of the following is NOT an example of a chemical change?


Question 5 options:


Baking soda and vinegar foam and erupt like a volcano.



Water evaporates into steam.



A hand warmer heats up after you squeeze it.



An antacid tablet neutralizes stomach acid.


Question 6 (2 points)

Saved

Question 6 options:

Boyle’s Law: When

temperature

is held constant, the pressure and volume of a gas are

inversely

proportional.

Question 7 (2 points)

Saved

Question 7 options:

Anytime that a substance changes size, shape, or temperature it would be considered a

physical

change. But, if it changed properties such as its density, pH, or how it reacts with other substances it is most likely a

chemical

change.

Question 8 (2 points)

Saved

Use the diagram below to correctly match the statements that follow.




Question 8 options:


1

Has the most kinetic energy



3

Has the least kinetic energy



1

Has an undefined volume and shape



3

Has a defined shape and volume



2

Has a defined volume but not a defined shape


1.

A


2.

B


3.

C


Question 9 (3 points)

Use the diagram below to answer the questions that follow for 1 point each.




Predict the change seen in the balloon in the freezer

Explain your prediction

Use the equation to provide additional support for your prediction



Question 9 options:

Question 10 (3 points)

Use the diagram below to answer the questions that follow for 1 point each.




Define Boyle's Law as demonstrated in the graph above

Predict the pressure if the volume is at 100

Predict the volume if the pressure is at 80 Kpa

Question 10 options:

Question 11 (3 points)

Use the diagram below to address the following questions for 1 point each:




Identify the beaker with the LOWEST amount of kinetic energy

Identify the beaker with the HIGHEST amount of kinetic energy

Explain the relationship between kinetic energy and thermal energy



Question 11 options:

Question 12 (6 points)

A balloon holds 50.0 mL of nitrogen at 25° C and a pressure of 736 mm Hg.


Answer the following questions for 2 points each:


According to Boyle's Law, what would have to change to double the pressure in the balloon?

According to Charles' Law, what would have to change to double the volume of the balloon?

Explain how the kinetic energy of molecules explains both Boyle's and Charles' Laws.