Chemical Change

Question 1

What is the mass number of an atom?

Answer 1

Mass is the total number of protons and neutrons in an atom’s nucleus.

Question 2

What does the atomic number represent?

Answer 2

The atomic number represents the number of protons in an atom, which determines the element.

Question 3

What are the chemical formulas for hydrochloric, sulfuric, and nitric acids?

Answer 3

Hydrochloric acid: HCl
Sulfuric acid: H₂SO₄
Nitric acid: HNO₃

Question 4

Name three common gases and their chemical formulas.

Answer 4

Hydrogen: H₂
Carbon dioxide: CO₂
Oxygen: O₂

Question 5

What is the reaction between magnesium and hydrochloric acid?

Answer 5

When magnesium reacts with hydrochloric acid, it produces magnesium chloride and hydrogen gas.

Question 6

How can you test for the presence of hydrogen gas?

Answer 6

To test for hydrogen, bring a lit splint near the gas. If there’s a “pop” sound, the test is positive for hydrogen gas.

Question 7

How can you test for carbon dioxide gas?

Answer 7

Bubble the gas through limewater. If the limewater turns cloudy, it confirms the presence of carbon dioxide.

Question 8

How can you test for oxygen gas?

Answer 8

Insert a glowing splint into the gas. If the splint re-ignites, the gas is oxygen.

Question 9

What is the electron arrangement of potassium, and how does it relate to its position on the periodic table?

Answer 9

Potassium has an electron arrangement of 2,8,8,1. It has one valence electron, placing it in Group 1, and uses four electron shells, placing it in Period 4.

Question 10

What does Ca stand for in the periodic table

Answer 10

Calcium

Question 11

What does K stand for in the periodic table

Answer 11

Potassium

Question 12

What does Cl stand for in the periodic table

Answer 12

Chlorine

Question 13

What does NE stand for in the periodic table

Answer 13

Neon

Question 14

What does Ag stand for in the periodic table

Answer 14

Silver

Question 15

Write a balanced equation for the reaction between magnesium carbonate and hydrochloric acid.

Answer 15

Magnesium carbonate + Hydrochloric acid → Magnesium chloride + Carbon dioxide + Water.

Question 16

What is the name for the horizontal elements in the periodic table

Answer 16

Periods

Question 17

What is the name for the vertical elements in the periodic table

Answer 17

Groups

Question 18

What are the 3 substance classifications

Answer 18

Mixture, Compound, Elements

Question 19

Define Mixture as a classification

Answer 19

Physical combinations of two or more substances, that can be separated by physical methods

Question 20

Define Compounds as a classification

Answer 20

Pure substances formed when two or more elements are chemically bound in fixed ratios like water (H20)

Question 21

Define Element as a classification

Answer 21

Pure substances consist of only one type of atom like oxygen (O), and gold (AU), and cannot be broken down further.

Question 22

Give me examples of element substances

Answer 22

Oxygen (O), Gold (Au), Carbon (C), Hydrogen (H2)

Question 23

Give me examples of mixture substances

Answer 23

Saltwater, Air, Soil, Salad, Concrete

Question 24

Give me examples of compound substances

Answer 24

Water ( H2O), Cabron Dioxide ( CO2), Sodium chloride (NaCI).

Question 25

Adding hydrochloric acid to small pieces of magnesium metal, what gas is produced in the experiment

Answer 25

Hydrogen Gas

Question 26

adding manganese dioxide to a solution of hydrogen peroxide solution, what gas is produced in the experiment

Answer 26

Oxygen gas

Question 27

adding hydrochloric acid to a small piece of magnesium carbonate powder what gas is produced in the experiment

Answer 27

Carob dioxide gas

Question 28

Write a balanced equation for the reaction between magnesium metal and hydrochloric acid.

Answer 28

Magnesium + Hydrochloric = Magnesium Chloride + Hydrogen gas.