Element/Compounds/chemical changes

Which statement best describes an element?

• made from mixture 
• thousands in the world
• pure, made of only one thing
• can be separated 

__ is a pure substance containing two or more kinds of atoms.

• Element

• compound

• mixture

• solution

How many elements are in H₂O?

• 1
• 2
• 3
• 4

Which example is a compound?

• N₂

• Cu

• O₂

• H₂O₂

Which best describes a compound? 

• found on the periodic table 
• made from two or more elements
• a pure substance 
• only 100 in the world 

Is salt NaCl a compound or a element?

• Element
• Compound

Which of the following does NOT identify a formation of a new substance?

• A gas is produced

• one liquid dissolves into the other

• The temperature changes

• A solid is formed

How many different elements are represented in the compound?
Fe₃O₄

• 2
• 3
• 1
• 4

A student observed bubbling and fizzing when he mixed baking soda and vinegar. What can the student conclude?

• A chemical reaction produced a solid

• No chemical reaction occurred

• Physical change

• A chemical reaction produced a gas

A teacher places a small amount of sugar in a a beaker and heats it over a candle. What chemical change properties has occurred?

• The sugar turns black

• The sugar gets larger

• The sugar turns into a liquid

• The sugar gets hotter