Chemistry 1st Semester Exam

Which of the following is a chemical change?

• Iron rusting 
• Glass breaking
• Clothing ripping
• Hair cut

What is the law of conservation of matter?

• Matter changes when reacted or changed.
• The mass of all reactants are changed during a physical or chemical change.
• The mass of the reactants is the same as the mass of the products.
• The mass of the products is different than the mass of the reactants.

This number is used to represent the number of each atom being represented.  What is the name of this number? 

• An Exponent
• The Coefficient
• A Molecule
• The Subscript

How many hydrogen atoms are in this chemical formula: 

• 4 hydrogen atoms
• 1 hydrogen atom
• 2 hydrogen atoms
• 3 hydrogen atoms

The atomic number of oxygen is

• 8

• 15.9994

• 16

• O

The number of electrons in a Lithium atom is

• 3

• 4

• 6

• 7

Electrons are

• Positively charged particles

• Negatively charged particles

• Neutral

A group of elements that are shiny, conduct heat and electricity well is called

• Metals

• Non-metals

• Metalloids

What is made up two or more elements that are chemically combined?

• Atom

• Element

• Compound

• Mixture

What does the nucleus of an atom contain?

• Electrons and neutrons

• Protons and neutrons

• Electrons and protons

• DNA