science final 1/24/25

Question 1

What caused the Flint water crisis?

Answer 1

The water source was switched to the Flint River without proper treatment, causing lead contamination due to corroding pipes.

Question 2

What was one of the major health impacts of the Flint water crisis?

Answer 2

Lead poisoning, especially affecting children, which can lead to developmental and neurological issues.

Question 3

Which type of reaction absorbs heat?

Answer 3

Endothermic reactions.

Question 4

Which type of reaction releases heat into the surroundings?

Answer 4

Exothermic reactions.

Question 5

Give an example of an endothermic reaction.

Answer 5

Photosynthesis, melting ice.

There are multiple right answers for this one! :D

Question 6

Give an example of an exothermic reaction.

Answer 6

Combustion of wood or gasoline.

Question 7

In a Bohr model, what determines the number of electrons?

Answer 7

The atomic number of the element.

Question 8

How do you determine the number of protons in an atom?

Answer 8

The number of protons is equal to the atomic number of the element.

Question 9

What is the maximum number of electrons that can be placed in the second energy level?

Answer 9

8 electrons.

Question 10

What charge do neutrons have?

Answer 10

Neutrons have no charge (neutral).

Question 11

Which subatomic particle orbits the nucleus of an atom?

Answer 11

Electrons.

Question 12

What is the charge of a proton?

Answer 12

Positive.

Question 13

What group contains the noble gases?

Answer 13

Group 18.

Question 14

Where are metals typically located on the periodic table?

Answer 14

Metals are typically on the left side and center of the periodic table.

Question 15

What properties do alkali metals (Group 1) have?

Answer 15

Alkali metals are highly reactive, soft, and have one valence electron.

Question 16

What is an example of an element?

Answer 16

Oxygen (O).

of course there are many answers 🙃

Question 17

What is an example of a compound?

Answer 17

Sodium chloride (NaCl).

Question 18

What is an example of a mixture?

Answer 18

Salad

Question 19

Can a mixture be separated by physical means?

Answer 19

Yes, mixtures can be separated by physical methods.

Question 20

Is this equation balanced?
H2 + O2 → H2O

Answer 20

No, the equation is unbalanced because the number of atoms of hydrogen and oxygen is different on both sides.

Question 21

Is this equation balanced?
2H2 + O2 → 2H2O

Answer 21

Yes, it is balanced because the number of atoms of each element is the same on both sides.

Question 22

What is a synthesis reaction?

Answer 22

A synthesis reaction occurs when two or more substances combine to form a new compound.
Example: A + B → AB.

Question 23

What is a decomposition reaction?

Answer 23

A decomposition reaction occurs when a compound breaks down into simpler substances.
Example: AB → A + B.

Question 24

What happens in a double displacement reaction?

Answer 24

Two compounds react and exchange parts to form two new compounds.
Example: AB + CD → AD + CB.

Question 25

What pH range do acids fall into?

Answer 25

pH less than 7.

Question 26

What pH range do bases fall into?

Answer 26

pH greater than 7.

Question 27

If a substance has a pH of 3, is it an acid or a base?

Answer 27

Acid.

Question 28

If a substance has a pH of 10, is it an acid or a base?

Answer 28

Base.

Question 29

What is a neutralization reaction?

Answer 29

A neutralization reaction is a chemical reaction between an acid and a base to produce a salt and water.
Ex. HCl + NaOH → NaCl + H2O

Question 30

What happens to the pH of a solution during a neutralization reaction?

Answer 30

The pH moves closer to neutral (pH 7).