Chemistry Unit Review UPDATED

Question 1

Is this a compound or element?

Accepted Answer

Neither

Question 2

Which group of the periodic table is the most reactive?

Accepted Answer

Alkali Metals

Question 3

A student is studying calcium; which characteristic is most related to its chemical reactivity?

Accepted Answer

The 2 valence electrons in each atom of calcium

Question 4

Which of the following is the correct way to write the formula of water?

Accepted Answer

H2O

Question 5

What needs to go into the box to make the equation balanced? ⇫Al3 + 6La2 → 12LaAl

Accepted Answer

4

Question 6

What subatomic particle(s) make(s) up the nucleus?

Accepted Answer

Protons and Neutrons

Question 7

In a chemical formula, which side are the reactants located?

Accepted Answer

Left

Question 8

Which of the following is a chemical change?

Accepted Answer

Burning

Question 9

The vertical lines in the periodic table are called...

Accepted Answer

Families, Groups

Question 10

How many valence electrons does Carbon have?

Accepted Answer

4

Question 11

An atom has 25 protons, 30 neutrons, and 25 electrons. What's the charge of the atom’s nucleus?

Accepted Answer

+25

Question 12

Define chemical change.

Accepted Answer

A change in the arrangement of the atoms

Question 13

True or false: This formula is unbalanced. 6CO2+6H2O → C6H12O6+6O2

Accepted Answer

False

Question 14

Elements in the same family have similar ______________ and ______________ properties.

Accepted Answer

Physical, Chemical

Question 15

True or false: This equation is unbalanced. 2Fe+S2 = FeS2

Accepted Answer

True

Question 16

What does the Law of Conservation of Mass state?

Accepted Answer

Matter cannot be created, Matter cannot be destroyed

Question 17

How many elements are in this formula: Be3Al2SiO6 (Emerald)

Accepted Answer

4

Question 18

BONUS: Can you answer this question from the 2013 10th Grade Chemistry STAAR?

Accepted Answer

Nuclear fission occurs because a nucleus is being split

Question 19

Is this equation balanced? 4CuAu2 → 4Cu + 2Au

Accepted Answer

Yes

Question 20

Why does Sodium Chloride dissolve with water but sodium react violently with water?

Accepted Answer

Compounds have different chemical properties

Question 21

What are valence electrons?

Accepted Answer

Electrons in the outermost ring

Question 22

An atom of an element has 36 protons and mass number of 84. How many neutrons are in this atom?

Accepted Answer

48

Question 23

A building is on fire and several papers burn. What change is burning paper and why?

Accepted Answer

Chemical, the paper is now a new substance

Question 24

Answer this question that was previously used in the 2015 8th Grade Science STAAR:

Accepted Answer

Strontium

Question 25

Is the following a compound or an element?

Accepted Answer

Element

Question 26

How do we find the number of neutrons in an atom?

Accepted Answer

Mass Number - Atomic Number

Question 27

REVIEW: What do you use to measure volume?

Accepted Answer

Graduated Cylinder, Ruler

Question 28

Jamie draws a Bohr model & draws 19 electrons. How many protons are needed to make it neutral?

Accepted Answer

19

Question 29

Which of the following is an INDICATOR of a chemical change?

Accepted Answer

Precipitate forms

Question 30

If the reactants had a mass of 103g, then what will be the mass after a chemical reaction?

Accepted Answer

103g because matter can't be created nor destroyed

Question 31

Which of the following has a negative charge?

Accepted Answer

Electrons

Question 32

Most elements in the periodic table are...

Accepted Answer

Metals

Question 33

Caroline melts a bar of iron. What change is this?

Accepted Answer

Physical

Question 34

Looking at a periodic table, how many valence electrons are there in Iodine (I, 53)?

Accepted Answer

7

Question 35

Which particles are exchanged in bonding?

Accepted Answer

Electrons

Chemistry Unit Review UPDATED

Questions 35

Chemistry Unit Review UPDATED

Questions 35