lesson1(recap, atomic radius, nuclear reaction)

another term for proton number

atomic number

another term for nucleon number

mass number/atomic mass

what do cations and anions do

lose + and gain electron -

what does the nucleus of an atom consist of

protons and neutrons

what does it mean by nuclear charge

number of protons in the nucleus

what is the nuclear charge of hydrogen( must indicate +)

+1

what is the nuclear charge of oxygen

+8

what force causes nucleus of an atom to be attracted to the electrons

electromagnetic force

what components of atoms take part in chemical reactions

valence electrons and neutrons

What is the octet rule?

atoms tendency to have 8 valence electrons (lose or gain)

what is duplet rule and how is it different to octet rule

want 2 valence electrons instead of 8

how can one determine atom identity

by its proton(atomic)number

what is natural abundance

percentage of how abundant the isotope is of a particular element

what happens when you add all the natural abundance of every isotope together

get 100%

formula of relative atomic mass

(nucleon number x natural abundance)+...../100

(everything divide 100 for percentage)

what to do if only have relative atomic mass with isotopes nucleon number and want to find out natural abundance of each isoptope

use variable x for natural abundance so 1 is x 1 is 100-x

what is common for all respective groups

same number of valence electrons (thus similar chemical properties)

what is common for respective periods

same number of electron shells

which group has alkali metals

group 1

which group has alkaline metals

group 2

which group has halogens

group 7 /17(in other periodic tables)

difference between alkaline and alkali metals

alkaline metals is less reactive

what is shielding effect

decrease in FOA exerted by nucleus on valence electrons due to Prescence of inner shells

what happens to FOA in atoms as inner shells increasse

decrease

due to shielding effect what happens to atomic radius when inner electron shells increase

atomic radius increase(valence electrons not held tightly)

across a period does atomic radius increase or decrease

decrease(proton increase =electron increase -more inner shells)

across a period does atomic radius increase or decrease

decrease
(still same number of electron shell but increase electrons hence more attracted to nucleus so atomic radius decrease)

what is electronegativity

ability to draw shared electrons to itself

how to know if an element has stronger electronegativity

increase across period

Why electronegativity increases across a period

greater nuclear charge smaller atomic radius

why electronegativity decreases down a group

going down atom increase size (more electron shells)

what is electromagnetic radiation

light like alpha beta...

what happens during alpha decay

a pair of protons and pair of neutrons bind together (helium atom)
check how to write equation

what is beta decay

one neutron change to proton
(gain electron- another element-check how to write in one note)is -1

what is positron emission

proton to neutron(liek cation so +1

what is electron emission/capture

electron react with proton form neutron

what determines stability of nuclei

ratio of protons and neutrons

what happens when nuclei is unstable

undergo radioactive decay