Chapter 2

Question 1

elements

Answer 1

92 Naturally occurring, 25 essential to human life

Question 2

compound

Answer 2

combination of elements

Question 3

atoms

Answer 3

smallest unit of matter that still retains the properties of an element. protons (+), Electrons (-), Neutrons (neutral)

Question 4

mass #

Answer 4

Sum of protons and neutrons

Question 5

atomic #

Answer 5

of protons

Question 6

isotopes

Answer 6

atoms that contain the same # of protons but different # of neutrons

Question 6

electrons

Answer 6

orbit at specific distances from the nucleus. the further away they are, the less energy.

Question 7

electron movement

Answer 7

when electrons move away, they absorb energy. when electrons move closer, they loose energy. closer if more potential energy, further is less potential energy.

Question 8

electron shells

Answer 8

each shell holds a specific # of electrons

Question 9

valence electrons

Answer 9

the number of electrons in the outer shell

Question 10

valency

Answer 10

the # of unpaired electrons in the valence shell

Question 11

electron orbital

Answer 11

the 3 dimensional space where electrons spend 90% of their time. can hold 2 electrons in each orbital

Question 12

covalent bonds

Answer 12

atoms that share valence electrons (non-metals)

Question 13

electronegativity

Answer 13

the attraction of an atom for the electrons of a covalent bond (Florine is the most)

Question 14

ionic bonds

Answer 14

bonds that donate their valence electrons to other atoms

Question 15

Cation

Answer 15

when an atom gives up an electron (+)

Question 16

anion

Answer 16

when an atom receives an electron (-)

Question 16

hydrogen bonds

Answer 16

bonds when an hydrogen atom that is already bonded to an electronegative atom is attracted to another strongly electronegative atom (weak bonds)