Atomic Structure Flashcards
What is an atom?
Everything is made up of atoms
An atom has a central nucleus composed of protons and neutrons with electrons orbiting around it.
What is an atom made out of?
- Central nucleus made of protons and neutrons
* Electrons orbiting in shells around the nucleus
Protons mass and charge
Mass - 1
Charge - +1
Neutrons mass and charge
Mass - 1
Charge - 0
Electrons mass and charge
Mass - 0
Charge - -1
Atomic number/ proton number
Number of protons
Mass number
Protons and neutrons
Electrons are weightless
Do atoms have an overall charge
No, unless it’s an ion
How many electrons can there be on each ring
First ring - 2
The rest - 8
What are isotopes?
Different versions of the same element.
The same amount of protons
Different amount of neutrons
How can you write in isotope notation
Eg. Carbon 12
Carbon 12 - 12 < - mass number
C
6. < - atomic number
What is relative atomic mass?
Ar
The weighted average of the masses of different isotopes of an element - taking the abundance into account
What is the formula for Ar
Ar = (mass x abundance) + (mass x abundance)
————————————————————-
100
What is the relative atomic mass of
Chlorine35 (75% of the time)
and
Chlorine37 (25% of the time)
Ar = (35x75) + (37x25)
——————————
100
What is the relative formula mass?
Sum of the Relative Atomic Masses in a formula Eg H2O H=1 1x2=2 O=16 16 + 2 = 18