2.1 atoms and reactions

is the chemical properties of isotopes the same or different?

• same

• electrons are what determine the chemical properties of an element, and because isotopes of an element have the same number of electrons, they also have similar chemical properties

do isotopes have the same or different physical properties?

• different

• neutrons add mass to the atom, so physical properties like mass and density change

what is a mass spectrum

it can be used to calculate the relative atomic mass of an element

process of mass spectrometry

1. sample is vapourised

2. sample is ionised from positive ions

3. ions are accelerated (heavy ions move more slowly and are less deflected)

4. ions are deflected as mass to charge ratio (m/z)

what are ionic equations?

• equations that leave out spectator ions (the ions that don’t react)

• in aqueous solutions, ionic compounds dissociate into ions

what are polyatomic ions?

ions made from more than one type of atom

examples of polyatomic ions

• SO4²-

• OH-

• NO3-

• NH4+

what are some examples of cations?

• silver- Ag+

• ammonium- NH4+

• zinc- Zn²+

what are some example of anions?

• carbonate- CO3²-

• hydrogen carbonate- HCO3-

• phosphate- PO4³-

• nitrate- NO3-

• hydroxide- OH-