Chemistry 3.2 Flashcards
Relative Atomic Mass definition
The average mass of all the isotopes of an element compared to1/12th of the mass of carbon-12
Isotopes definition
Different forms of the same element with the same number of protons but different numbers of neutrons.
How do you calculate RAM?
(mass x abundance) + (mass x abundance) divided by 100
How to explain the number of occupied electron shells
Look at which period the element is in. E.g. Potassium is in period 4 so it has 4 occupied electron shells.
How to explain number of outer shell electrons
Look at which group the element is in. E.g. Nitrogen is in group 5 and has 5 outer shell electrons.
How to find number of protons.
Same as atomic number
How to find number of neutrons
Mass number - atomic number
How to find number of electrons
Same as atomic number or proton number
Relative mass of proton
1
Relative mass of neutron
1
Relative mass of electron
1 divided by 1836 or 0.0005
What are neutral atoms?
Atoms with the same number as positive protons as negative electrons.
Atomic number meaning
Number of protons in the nucleus of an atom.
Which subatomic particles are found in the nucleus?
Protons and neutrons.
What are electron shells?
The region surrounding the nucleus where electrons orbit the nucleus.
How many electrons can the first electron shell hold?
2
How many electrons can the 2nd and 3rd electron shells hold?
They can each hold 8.
How many electrons can the 4th electron shell hold?
18 electrons.
Atomic mass definition.
Number of protons + number of neutrons in an atom in an element.
How to write electron structure
Example- Calcium: 2, 8, 8, 2
