Chapter 2- Atoms, Ions and compounds

isotope meaning?

2 or more atoms of an element with the the same number of protons (atomic number) but different number of neutrons and therefore a different mass number

relative isotopic mass meaning?

mass of an element compared with 1/12th mass of carbon-12

relative atomic mass meaning?

weighted mean mass of an atom of an element compared 1/12th mass of an atom of carbon-12

properties of isotopes?

• chemical properties of isotopes are identical

• physical properties (such as density) are different

mass of proton, neutron and electron?

proton- 1.672 × 10^-27

neutron- 1.675 × 10^-27

electron- 9.109 × 10^-31

charge of proton, neutron and electron?

proton- 1.602 × 106-19

what is a salt?

• when the H+ ion in an acid is replaced by a metal ion

what is an ion, and what are the two types?

an ion is a charged atom. the number of electrons is different from number of protons

• positive ions (cation) are atoms with fewer electrons than protons

• negative ions (anion) are atoms with more electrons than protons

what is atomic number and mass number represented by?

• atomic number is represented by letter ‘Z’

• mass number is represented by letter ‘A’

Polyatomics needed to know?

• Ammonium- NH4-

• Hydroxide- OH-

• Nitrate- NO3-

• Hydrogencarbonate- HCO3-

• Manganate (VII)- MnO4-

• Carbonate- CO3 2-

• Sulfate- SO4 2-

• Sulfite- SO3 2-

• Dichromate (VI)- Cr2O7 2-

• Phosphate- PO4 3-

what does ionic bonding occur between?

it occurs between a metal and a non-metal

• electrons are transferred from the metal to the non-metal to achieve full outer shells

• when they are transferred, it creates charged particles called ions