Chapter 2 Flashcards
When an electron is moved further from the nucleus
a. its potential energy may change, depending on how the electron was moved
b. it loses potential energy
c. it gains potential energy
d. its potential energy is unchanged
C
How many electrons does it take to fill the first electron shell of a carbon atom?
a. 4
b. 2
c. 1
d. 8
B
How many covalent bonds do hydrogen atoms need to form with other atoms to complete their valence shell?
a. 3
b. 4
c. 1
d. 2
C
When we write “O=O”, the double line represents
a. two ionic bonds between the oxygen atoms
b. two electrons shared by the oxygen atoms
c. two covalent bonds between the oxygen atoms
d. two protons shared by the oxygen atoms
C
Nitrogen (N) is more electronegative than hydrogen (H). Which of the following statements is correct about ammonia (NH3)?
a. Each hydrogen atom has a slight negative charge.
b. Each hydrogen atom has a partial positive charge.
c. The nitrogen atom has a strong positive charge.
d. There are covalent bonds between the hydrogen atoms.
B
How many covalent bonds do nitrogen atoms need to form with other atoms to complete their valence shell?
a. 3
b. 2
c. 4
d. 1
A
How many covalent bonds do carbon atoms need to form with other atoms to complete their valence shell?
a. 4
b. 1
c. 2
d. 3
A
Molecules are
a. two or more atoms joined by ionic bonds
b. two or more atoms joined by covalent bonds
c. two or more atoms joined by hydrogen bonds
d. all of these answers are correct
B
Electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient energy, a possible result is that
a. an electron may move to an electron shell closer to the nucleus.
b. the atom may become a radioactive isotope.
c. the atom would become a negatively charged ion, or anion.
d. an electron may move to an electron shell farther away from the nucleus
D
Water is an example of
a. only a molecule
b. only a compound
c. both a compound and a molecule
d. neither a compound nor a molecule
C
How many more electrons do oxygen atoms need to complete their valence shell?
a. 1
b. 4
c. 2
d. 6
C
Depending on how far an electron is moved from the nucleus
a. you can decrease its potential energy by only certain amounts
b. you can decrease its potential energy by any amount
c. you can increase its potential energy by only certain amounts
d. you can increase its potential energy by any amount
C
If you make a model of a methane (CH4) molecule, the overall shape of the molecule will most closely resemble
a. a straight line
b. a wide “V”
c. a pyramid
d. a square
C
Which of the following statements regarding atomic particles is correct?
a. Electrons are negatively charged, protons are neutral and neutrons are neutral.
b. Electrons are negatively charged, protons are positively charged and neutrons are neutral.
c. Electrons are negatively charged, protons are positively charged and neutrons are positively charged.
d. Electrons are negatively charged, protons are positively charged and neutrons are negatively charged.
B
Magnesium is an example of
a. an organic substance
b. an element
c. a molecule
d. a compound
B