1) analyze the diagram below. which of the following is true about the sodium (na) atom after the electron moves to chlorine?
a
it has a negative charge.
b
it becomes a positive ion.
c
it becomes an isotope.
2) analyze the diagram below. which term best describes what is formed in the diagram?
a
ionic bond
b
covalent bond
c
polar molecules
3) analyze the diagram below. what do the yellow lines stand for?
a
negative charges
b
hydrogen bonds
c
positive charges
4) water’s high heat capacity protects organisms in the ocean from what?
a
drastic changes in temperature
b
floating to the surface
c
strong ocean currents
5) which statement best describes an effect of the low density of frozen water in a lake?
a
when water freezes, it contracts, decreasing the water level in a lake.
b
water in a lake freezes from the bottom up, killing most aquatic organisms.
c
when water in a lake freezes, it floats, providing insulation for organisms below.
6) what property of water allows some insects to walk on a pond’s surface?
a
adhesion
b
cohesion
c
density
7) which of the following represents an ion?
a
a particle that has 12 protons, 11 neutrons, and 12 electrons.
b
a particle that has 9 protons, 9 neutrons, and 10 electrons.
c
a particle that has 14 protons, 14 neutrons, and 14 electrons.
8) why are compounds different from single elements?
a
when elements form a compound, the bonds and structure of the elements change.
b
when elements form a compound, the masses of the elements increase.
c
when the elements form a compound nothing is different.
9) which of the following explains the formation of the curved surface of water in the graduated cylinder shown below?
a
ionic bonds form between glass molecules in the cylinder.
b
covalent bonds form between water molecules and glass molecules in the cylinder.
c
attractive forces form between polar water molecules and polar glass molecules in the cylinder create the meniscus.