Science 9 - Chapter 2 Chem

how many natural occurring elements are there on earth

92

what are elements represented by and how many letters?

symbols and 1-2 letters

what does the atomic number stand for

number of protons

how to calculate neutrons?

atomic mass - protons

what is an atomic mass

the total mass of a single atom

what is the number of electrons in an atom

same number of protons

where are metals located on the periodic table

left side

what does AMU stand for

atomic mass unit

where are non metals located on the periodic table

right side

where are metalloids located on the periodic table

on the staircase between non metals and metals

what are the properties of metals

hard

shiny

malleable

ductile

good conductors

what are the properties of non metals

usually gases or brittle solids at room temperature

do not have properties of metals

what properties do metalloids have

have properties of both metals and non metals

which way do periods go

horizontal (left n right)

which way do families go

vertical (up n down)

what is a family

elements that have the similar properties to eachother

periods are label from

1-7

families are label by

1-18

which family is most reactive

alkali metals

what charge does alkali metals form when making ions

+1 charge

which family is less reactive than alkali metals

alkaline earth metals

what type of charge does alkaline earth metals have

+2

which family is non metal and highly reactive

halogens

what type of charge does halogens have

-1 charge

which family is unreactive and stable

nobel gases

what type of charge do nobel gases have

no charge

what is a valence electron

it’s the electron(s) in the last orbital

what does it mean if the last orbital isn’t full

highly reactive and not stable

what does it mean if the last orbital is full

unreactive and stable

how many electrons can the 1st orbital hold

2

how much electrons in the 2nd n 3rd orbital

8

how many electrons in 4th n 5th orbital

18

how many electrons in the 6th n 7th orbital

32

what do u add to a bohr model of an ion

brackets and the charge