MULTIPLE CHOICE: Choose the letter of the best answer.

1.Which of the following is a common sign that a chemical change has occurred?
a. A chemical has changed size.
b. A chemical has changed to a different state (solid, liquid or gas)
c. A chemical has become a different shape.
d. A chemical has turned a different color.

2. Which of the following does NOT show a chemical change?
a. Change of state of matter
b. production of gas
c. Color change
d. change in size

3. Curdling of milk is an example of what chemical evidence?
a. formation of gas
b. change in temperature
c. evolution of heat and light
d. formation of precipitate

4. It is a substance that is present at the start of a chemical reaction.
a. reactant
b. product
c. catalyst
d. heat

5 . According to this law, the mass of the products in a chemical reaction must equal the mass of the reactants.

a. Law of Motion
b. Law of Inertia
c. Law of Matter
d. Law of Mass Conservation

6. What do you call the substance that is present at the end of a chemical reaction?

a. reactant
b. catalyst
c. product
d. heat

7. Matter is made of tiny indivisible particles called___________.
a. atom
b. molecule
c. compound
d. element



8. A ______ is a combination of two or more atoms
a. ion
b. mole
c. molecule
d. element

9. An element and an atom are different but related because
a. particular element is made up of many different types of atoms
b. A molecule is the same as an atom
c. An element is made up of all the same type of atom
d. An element is smaller than atom

10. All matters are made up of atoms, who is the scientist presented a concrete evidence that all matter is made up of atoms.
a. Aristotle
b. Leucippus
c. Dalton
d. Democritus

11. Analogy
JJ Thomson: Discovered the electron: James Chadwick: _________
a. discovered the proton
b. discovered the atom
c. discovered the nucleus
d. discovered the neutron

12. Which conclusion was a direct result of the gold foil experiment?
a. An electron has properties of both waves and particles
b. An atom is composed of at least three types of subatomic particles
c. An atom is mostly empty space with a dense, positively charges nucleus
d. The electron has a positive charge and is located inside the nucleus

14. Which of the following are parts of Dalton’s Theory?
a. All substances are made up of atoms
b. Atoms join with other atoms to make new substances
c. Atoms of different elements are different
d. All of these are part of his theory

15. Bohr’s contribution to the development of atomic structure
a. was referred to as the “plum pudding model.”
b. was the discovery that electrons surround a dense nucleus.
c. was proposed that electrons travel in circular orbits around the nucleus.
d. is the quantum mechanical model.

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