Atomic Structure Flashcards
(16 cards)
Name the three subatomic particles
Proton, neutron electron
What subatomic particles are in the nucleus?
Proton and neutron
Relative charge of each subatomic particle
Proton: +1
Neutron: 0
Electron: -1
Why are atoms neutrally charged?
Number of protons are equivalent to the number of electrons, so charges are neutralised
What happens when the atom loses an electron or gains an electron?
Loses electron: positively charged
Gain electron: negatively charged
Formula for mass of atom
Number of protons + number of neutrons
Difference between atomic mass and atomic number
Atomic mass (nucleon number) - total mass of atom (no. of protons + no. of neutrons)
Atomic number (proton number) - number of protons
What is the octet rule?
1st electron shell - up to 2 electrons
2nd electron shell and above - up to 8 electrons
How do you find out the period and group of an element based off its electronic configuration?
Period - number of electrons shells
Group - number of electrons in the outermost shell
What is an isotope?
Element that has the same number of protons and electrons but different number of neutrons
What chemical property does an isotope usually have if there’s more neutrons than protons?
Radioactive
What are the difference between properties in normal elements and isotopes?
Different physical properties - different mass
Similar chemical properties - same no. of valence electron
What is relative atomic mass (R.A.M)?
Number of times an average atom is heavier than 1/12 of a c-12 atom; takes account into abundance of the isotope of an element
Why is carbon-12 used to calculate R.A.M?
- mass of c-12 is exactly 12 atomic mass unit
- stable and abundant
- reliable reference
Why isn’t R.A.M usually a whole number?
Because it’s a weighted average of all naturally occurring isotopes, each with its own mass and abundance
Formula for calculating R.A.M
(a x X%) + (b x Y%)
