8th Grade Science Review (8.P.1.1, 8.P.1.2, 8.P.1.3, & 8.P.1.4)

Question 1

What is the best conclusion that can be made about element that readily reacts w/alkali metals?

Accepted Answer

It is in Group 17 (VIIA)

Question 2

What is the relationship between elements with 6, 14, & 82 protons on the periodic table?

Accepted Answer

They are in the same group.

Question 3

Which substance is most likely an element?

Accepted Answer

It is composed of one kind of atom

Question 4

Which two substances will most likely form a mixture when combined?

Accepted Answer

water and salt

Question 5

Which is the correct way to balance the following chemical equation? Al + O2 → Al2O3

Accepted Answer

4Al + 3O2 → 2Al2O3

Question 6

What physical property is characteristic of the group located in the rightmost column?

Accepted Answer

gas state at room temperature

Question 7

A balloon is filled with 1 liter of air. Which most likely causes an increase in the volume?

Accepted Answer

increase the temperature of the balloon

Question 8

Which is true about the way atoms of elements combine to form a compound?

Accepted Answer

Elements always combine in specific ratios.

Question 9

How many more atoms does hydrogen peroxide (H2O2) have than water (H2O)?

Accepted Answer

one

Question 10

How many atoms are in one formula unit of magnesium hydroxide, Mg(OH)2?

Accepted Answer

5

Question 11

How can mixtures best be described?

Accepted Answer

made of different elements not chemically bonded together

Question 12

Which best describes the reactivity of metals when moving from left to right on the PT?

Accepted Answer

They become less reactive

Question 13

A 2 step chem. reaction is shown. Approximately how many grams of CO2 are produced in Step 2?

Accepted Answer

9.57 grams

Question 14

When vinegar and baking soda are combined, a mixture & a gas are produced. Which is true?

Accepted Answer

Mass of the mixture & gas = Mass of vinegar & baking soda

Question 15

Which equation is balanced according to the Law of Conservation of Mass?

Accepted Answer

2NaCl + Mg → MgCl2 + 2Na

Question 16

Which set of coefficients will balance this chemical equation? ___C2H4 + ___O2 → 2CO2 + 2H2O

Accepted Answer

1, 3

Question 17

One magnesium (Mg) atom is most likely to bond with one atom of which element?

Accepted Answer

oxygen (O)

Question 18

Which represents a compound?

Accepted Answer

water

Questions 18