Elements of Chemistry

What is the difference between physical and chemical properties?

• Physical properties are observable characteristics, while chemical properties describe how a substance reacts with other substances.

• Physical properties describe how a substance reacts with other substances, while chemical properties are observable characteristics.

• Physical properties and chemical properties are the same thing.

• Physical properties and chemical properties are unrelated to each other.

Freezing is the change of state from

• Solid to gas
• Liquid to solid
• Gas to solid
• Liquid to gas

Name the compound: N₂O₅.

• dinitrogen pentaoxide

• binitrogen pentaoxide

• nitrogen oxide

• pentanitrogen dioxide

What is this element? ( Hg )

• Magnesium

• Calcium

• Aluminium

• Mercury

What is the element? (Pb)

• Tin

• Aluminium

• Chlorine

• Lead

Is the following equation balanced?

Al + O2 ---> 2Al2O3

• Yes

• No

During a chemical reaction, atoms ________.

• can appear

• can disappear

• get rearranged

• stop moving and vibrating

What is the left part of a chemical equation called?
2H_{2 +} O₂ --> 2H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

How many oxygen atoms are present in the following? 
4Ca(OH)₂

• 4
• 6
• 8
• 1

Balance this equation:

H2 + Cl2 ---> HCl

• It is balanced.

• H2 + Cl2 ---> 2HCl

• 3H2 + Cl2 ---> 6HCl

• H2 + 3Cl2 ---> 6HCl