4. The majority of an atom’s mass exists where?
a. in the nucleus
b. in the electron cloud
c. in the space between the nucleus and the electron
d. in the neutrons
a. in the nucleus
100
1. How do scientists know how atoms are structured?
a. By looking at them under a microscope
b. By running experiment that expose their properties
c. By examining only the largest atom
d. By splitting them apart
b. By running experiment that expose their properties
100
10. What do electrons in the same shell have in common?
a. they have same amount of energy
b. They are all positively charged
c. They are all made up of atoms
d. They all have neutral charges
a. they have same amount of energy
100
Water
H20
100
15. What can you conclude from the fact that electrons orbit far away from atomic nuclei?
a. electrons are extremely small
b. atoms are comprised mostly of empty space
c. protons have a positive charge
d. atoms consist of subatomic particles
b. atoms are comprised mostly of empty space
200
5. What are electrons?
a. Positively charged particles
b. Neutrally charged particles
c. Negatively charged particles
d. Uncharged particles
c. Negatively charged particles
200
2. What contribution did John Dalton make to atomic theory?
a. He discovered that every atom was positively charged
b. He discovered that every element consisted of one type of atom
c. He discovered that atoms had nuclei
d. He discovered that atoms could be divided into smaller parts
b. He discovered that every element consisted of one type of atom
200
11. Which of the following is an example of a subatomic particle?
a. carbon
b. oxygen
c. electron
d. hydrogen
c. electron
200
NaBr
Sodium Bomide
200
14. How are molecules different from atoms?
a. They consist of several atoms bonded together
b. They do not contain neutrons
c. They do not have nuclei
d. Their particles do not have electrical charges
a. They consist of several atoms bonded together
300
6. What does the nucleus of an atom contain?
a. Electrons and neutrons
b. Protons and neutrons
c. Neutrinos and positrons
d. DNA and RNA
b. Protons and neutrons
300
3. Place the following scientists in order, from the earliest to latest
A. Ernest Rutherford B. JJ Thompson C. John Dalton
A. B,C,A,
B. C,A,B
C. A,C,B
D. C,B,A
D. C,B,A
300
12. Oxygen has atomic number of 8. What can you conclude from this fact?
a. an atom of oxygen weighs 8 grams
b. an atom of oxygen has 4 protons and 4 electrons
c. an atom of oxygen has 8 positrons
d. an atom of oxygen has 8 protons
d. an atom of oxygen has 8 protons
300
MgO
magnesium Oxide
300
17. What characteristics are shared by all alkali metals and alkaline earth metals?
a. They conduct electricity very well
b. They are strong and shiny
c. They form alkaline solutions when mixed with water
d. They do not react with water at all
a. They conduct electricity very well
400
7. How are neutrons different from protons and electrons?
a. They are more massive than protons and electrons
b. They have no electrical charge
c. They are less massive than protons and electrons
d. Protons and electrons exist in atomic nuclei; neutrons orbit the nucleus in a “cloud”
b. They have no electrical charge
400
9. What is the significance of the periodic table of elements? Choose the best answer.
A. It lists all the different metals known to humans
B. It predicts and lists all the chemical elements in the universe
C. It explain where different atoms can be found
D. It proves that atoms are the building blocks of matter
C. It explain where different atoms can be found
400
16. 6C12, what does the number 12 represent?
a. an atomic number
b. a number of electrons
c. an atomic mass
d. a chemical symbol
c. an atomic mass
400
Sodium Phosphate
Na2PO4
400
18. Carbon has an atomic number of 6. What can you conclude about carbon from this fact?
a. it has 6 protons
b. it has 6 neutrons
c. it has 6 electrons
d. it has 6 positrons
a. it has 6 protons
500
8. How are electrons arranged in an atom?
a. in groups of five
b. in energy levels
c. by color
d. by shape
b. in energy levels
500
13. The word “atom” comes from a Greek word for “indivisible.” In what way are atoms indivisible?
a. They cannot be separated once they’ve bonded with other atoms
b. They cannot be broken apart without losing their chemical properties
c. They cannot form bonds with other atoms
d. They cannot gain or lose electrons
They cannot be broken apart without losing their chemical properties
500
9. What is the significance of the periodic table of elements? Choose the best answer.
A. It lists all the different metals known to humans
B. It predicts and lists all the chemical elements in the universe
C. It explain where different atoms can be found
D. It proves that atoms are the building blocks of matter
C. It explain where different atoms can be found
500
Be(OH)2
Beryllium Hydroxide
500
19. Noble gases are sometimes called “inert gases.” What can you infer abut the meaning of the word “inert” in chemistry?
a. it refers to substances that easily lose electrons
b. it refers to substances that do not react with other substances
c. it refers to substance that have strong electrochemical charges
d. it refers to gases
b. it refers to substances that do not react with other substances