8th Grade Unit 3 Intro to Chemistry Unit Review

What are the signs that a chemical reaction has occurred? (Choose all that apply.)

• Odor

• Temperature Change

• Precipitate

• Gas Production

• Color Change

The Law of Conservation of ​ (a)   states that mass is not created nor destroyed during a chemical reaction.

• Mass
• Energy

A chemical reaction occurs when bonds break and reattach to other atoms.

• True

• False

Which of the following is an example of a new substance being formed by a chemical reaction?

• A cake baking in the oven

• Water condensing

• Copper bending

• Neon sign glowing

There are ​ ​ (a)   atoms of Sodium, ​ ​ (b)   atoms of Carbon, ​ (c)   atoms of Hydrogen and ​ ​ (d)   atoms of Oxygen in Sodium Citrate, Na₃C₆H₅O₇.

• 3
• 6
• 5
• 7
• 9
• 10
• 1

There are ​ (a)   elements in Glucose, C₆H₁₂O₆.

• 3
• 6
• 12

CCl₄ has __________ elements and ________ total atoms.

• 5; 2

• 3; 6

• 2; 5

Element X and Element Y are in the same group.

• True

• False

Elements in a periodic table are arranged from left to right and top to bottom in order of ​ (a)   .

• atomic number
• atomic mass

The red area on the Periodic Table are:

• Noble Gases

• Nonmetals

• Metals

• Metalloids