Chem II Unit 2 Quiz 1

law of conservation of mass

atoms cannot be created or destroyed

law of constant composition/ definite proportions

in a given compound, number and type of atoms are constant

law of multiple proportions

elements can combine in different ratios by mass to form more than one compound

radioactivity

atoms with unstable nuclei spontaneously break down, undergo radioactive decay, bu emitting radiation

nucleus

where proton and neutrons are in the atom, takes up VERY small part of the atom’s volume

strong nuclear force

force keeping protons together in nucleus, overcoming electrostatic repulsion

atomic number

number of protons in a nucleus, symbolized with letter Z

mass number

sum of the number of protons and neutrons in an atom, symbolized with letter A

isotopes

atoms of the same element with different masses

atomic mass/weight

average mass of all naturally occurring isotopes considering relative abundances of each isotope

groups

columns on periodic table, have similar properties to each other

periods

rows

group 1

alkali metals

group 2

alkaline earth metals

group 16

chalcogens

group 17

halogens

group 18

noble gases

cation

positively charged ion, usually metals, named with either regular name if it has a fixed charge or a roman numeral to indicate charge

anions

negatively charged ions, usually nonmetals, named with changing end of name to “ide”

monoatomic ion

ion formed from single atom

set charges

Ag+, Zn2+, Cd2+, Al3+, N3-, P3-

1 Å (angstrom)

1×10^-10 m