periodic table grouping and vocab

atomic number

the number of protons in the nucleus of an atom of an element

mass number

the total number of protons and neutrons in an atom's nucleus

element

pure substance that consists entirely of one type of atom

atom

the smallest unit of an element that maintains the properties of that element

luster

ability to reflect light

malleable

able to be hammered into thin sheets

reactivity

the ease and speed with which an element combines, or reacts, with other substances

valence electrons

electrons on the outermost energy level of an atom (determines and elements reactivity)

physical property

a characteristic of a substance that can be observed without changing the identity of the substance

electron cloud

a region around the nucleus of an atom where electrons are likely to be found

isotope

one of two or more atoms with the same atomic number but with different numbers of neutrons

three groups of the periodic table

non-metals, metals and metalloids

properties of metals

☆ good conductors of electricity and heat
☆ ductile and malleable
☆ reaction with water is corrosion

properties of non-metals

☆ poor conductors
☆ not ductile or malleable
☆ brittle and dull
☆ many are gasses

properties of metalloids

☆ properties of metal and non-metals
☆ solids that are shiny or dull
☆ conduct heat but not as good as metals
☆ ductile and malleable

family

they have similar properties, organized into columns

period

horizontal rows, don’t have similar properties

hydrogen

Hydrogen has 2 valence electrons and is a gas at room temperature. It's very reactive and is never found uncombined.

group 1

☆ alkali metals
☆ 1 valence electron
☆ react with air to form caustic metal oxides
☆ shiny, consistency of clay

group 2

☆ alkaline earth metals
☆ 2 valence electrons
☆ very reactive, (not as much as group1)
☆ never found uncombined in nature
☆ shiny, soft (but harder than group 1 metals)

groups 3-12

☆ transition metals
☆ 1 or 2 valence electrons
☆ moderate (ex: Fe) to low reactivity (ex: Au)
☆ good conductors of heat and electricity
☆ compounds are usually brightly colored

group 13

☆ boron family
☆ 3 valence electrons
☆ moderately reactive
☆ includes a metalloid (boron) and the rest are metals

group 14

☆ carbon family
☆ 4 valence electrons
☆ unreactive
☆ includes a non-metal (carbon), metalloids and metals

group 15

☆ nitrogen family
☆ 5 valence electrons
☆ tend to share electrons when they bond
☆ moderately reactive

group 16

☆ oxygen family
☆ 6 valence electrons
☆ moderately reactive (oxygen is very reactive)
☆ most elements in this family share electrons when forming compounds

group 17

☆ halogen family
☆ 7 valence electrons
☆ react with alkali metals to form salts
☆ strong odors and interesting colors
☆ halogen atoms only need to gain 1 electron to fill their outermost energy level

group 18

☆ noble gases
☆ 8 valence electrons
☆ extremely unreactive
☆ inactive because their outermost energy level is full, called inert because they aren’t ready to combine with other elements

stable isotopes

they stay the same over time

unstable isotopes

will eventually decay into a different nucleus

when a nucleus emits a particle and changes identity, that process is called

radioactive decay

Isotopes that are unstable and undergo radioactive decay are called

radioactive isotopes

1:1

the most stable neutron to proton ratio

elements with a large number of protons are most stable when their neutron to proton ratio is ____. The more protons an element has, the ____ this ratio needs to be for the nucleus to be stable.

higher, higher

types of decay

alpha, beta - , and beta +

β− decay

too many neutrons compared with protons

β+ decay

too many protons compared with neutrons

positron

charge of +1, no mass, when they collide with an electron, both this particle and the electron get annihilated

α-decay

when the nucleus is too big overall, it can become more stable by losing both protons and neutrons

alpha particle

has 2 protons and 2 neutrons, same as the nucleus of a helium-4 atom

fission

splitting a nucleus into smaller parts, ex: power plants

fusion

combining nuclei to make something bigger, ex: stars

How many valence electrons does fluorine (F) have?

7

How many valence electrons does aluminium (Al) have?

3

How many energy levels does phosphorus (P) have?

3

Iron-50 has ___ protons and ___ neutrons.

26, 24

A calcium ion has a charge of +2 and a mass of 40. How many electrons does it have?

18

An oxygen ion has a charge of -2 and a mass of 17. How many protons does it have?

8

Strontium (Sr) shares common properties with what other element?

Barium (Ba)

All of the following are properties of metals EXCEPT
a. brittle
b. conducts elecricity well
c. malleable
d. lustrous

brittle

An isotope will undergo beta minus (electron) decay when

Its neutron to proton ratio is too high to be stable

A positron decay occurs, and the daughter isotope is Manganese-55. What was the parent isotope?

Iron-55

What particle is emitted when Barium-140 decays to Lanthanum-140?

electron

What particle is emitted when Potassium-38 decays to Argon-38?

positron