Exam 1 - Chapter 2

Question 1

atoms

Answer 1

building blocks of life

Question 2

matter

Answer 2

anything that takes up space

Question 3

element

Answer 3

substance composed of only one type of atom, cannot be broken down

Question 4

molecule

Answer 4

unit composed of two or more atoms joined by covalant bonds

Question 5

compound

Answer 5

unit composed of two or more elements that are joined by chemical bonds

Question 6

mixture

Answer 6

combination of 2 or more substances that do not chemically bond

Question 7

protons

Answer 7

positive charge in nucleus 1da/amu

Question 8

neutrons

Answer 8

neutral charge in nucleus 1da/amu

Question 9

electron

Answer 9

negative charge in orbitals negligible

Question 10

elements

Answer 10

atoms with same number of protons, OCHN=oxygen, carbon, hydrogen, nitrogen

Question 11

atomic number

Answer 11

number of protons

Question 12

mass number

Answer 12

sum of protons and neutrons

Question 13

atomic mass

Answer 13

weight mass of atoms of an element in daltons

Question 14

isotopes

Answer 14

atoms of an element that differ in number of neutrons

Question 15

radioisotopes

Answer 15

unstable nucleus decays spontaneously giving off particles and energy to return to stability

Question 16

radioactive decay

Answer 16

process of a radioisotope losing particles and energy over time

Question 17

electron orbitals

Answer 17

• house electrons
• filled from lower to higher energy
• farther an electron is from the nucleus, the greater its potential energy

Question 18

electron shells

Answer 18

1st - 2 electrons, each shell after = 8 electrons

Question 19

free radicals

Answer 19

uncharged solitary atoms with unpaired electrons

Question 20

ions

Answer 20

atoms with an unequal number of protons and electrons

Question 21

chemical bond

Answer 21

attractive force that arises between two atoms when their valence electrons interact

Question 22

ionic bonds

Answer 22

donation or theft of electrons results in ions, ions of opposite charge are strongly attracted to each other

Question 23

electromagnetically

Answer 23

measure of the ability of an atom to pull electrons away from other atoms

Question 24

polarity

Answer 24

separation of charge into partial positive and partial negative regions

Question 25

covalent bonds

Answer 25

atoms share a pair of electrons

Question 26

polar covalent

Answer 26

unequal sharing of valence electrons

Question 27

non-polar

Answer 27

equal sharing of valence electrons

Question 28

hydrogen bonds

Answer 28

partially positive hydrogen atom covalently bonded to one electronegative atom is attractive to another electronegative atom

Question 29

van der waals interactions

Answer 29

asymmetrically distributed electrons in molecules or atoms result in hot spots of positive or negative charge

Question 30

strength of bonds

Answer 30

covalent, iconic, hydrogen, van der waals

Question 31

H
H=C=H
H

Answer 31

non polar

Question 32

h-o-h

Answer 32

polar

Question 33

na1e -> Cl7e = Na Cl8e

Answer 33

ionic

Question 34

water —— water

Answer 34

hydrogen

Question 35

chemical reactions

Answer 35

O2 + 2H2 (reactants) =(reaction) 2H20 (product)