Atoms and alements

Atom

Smallest unit of an element 

The atomic nucleus contains

protons and neutrons.

Mass number for Proton and neutron is

1

what charge is proton

Positive

What charge is neutron 

Neutral charge 

Elements-

have a different numbers of protons and electrons. Number of protons defines an element but number of electrons can change. (electrons can be lost). 

 

Isotope-

Atoms that have the same number of protons and electrons but different numbers of neutrons of the same element.  

 

Going down grid is

group

Side of the table  is

period

whats Atomic mass and where is it

consists of what -

is the mass of element (on top) 

--->  Protons + neutrons 

Atomic number where is it and what does it consist 

number of protons in the nucleus which indicates properties of an element and its place on the periodic table. the bottom 

Avogadro's number is

6.02x1023

one mole of any substances contains this

Moles

unit of amount of a substance MOL 

Molar

unit of concentration of a substance MOL/L 

1st shell has how man electrons and orbitals

2 electrons

1 S orbital 

2nd shell has how man electrons and orbitals

8 electrons 

1 S orbital and 3 P orbitals  

3rd shell has how man electrons and orbitals

18 electrons

S orbital and 3 p orbitals and 5 D orbitals 

Core electrons-

filled shells closest to nucleus

Valence electrons-

outermost shell electrons  

Octet rule-

atoms will be more stable if they have filles s and p orbitals for their valence electrons. 

Loose and gain electrons from other atoms to achieve the full octet

Electronegativity

 the ability of an atom to attract electrons towards itself in a chemical bond

Ionisation energy

is losing an electron  

Electron affinity

is gaining a electron

Across a period electronegativity

increases AS greater number of protons _ greater attraction for electrons  

electronegativity down a group

Decreases atoms have more electron shells so big radius.