Answer:
See explanation
Explanation:
Molar mass is obtained as the sum of relative atomic masses as follow;
For CaBr = 40.08 + 79.90 = 119.98 g/mol
For BeBr = 9.012 + 79.90 = 88.912 g/mol
For CdBr2 = 112.41 + 2(79.90) = 272.21 g/mol
For CuBr2 = 63.55 + 2(79.90) = 223.35 g/mol
Answer:
a. The apparatus required to purify gypsum sample are: Bunsen burner, beaker, Filter Funnel, stirring rod, the filter paper.
b. Gypsum is a sulfate mineral that is made up of calcium sulfate dihydrate. Step-by-step instruction to purify gypsum sample is as follows:
1. Add water to the gypsum sample in a beaker.
2. Use the stirring rod to mix the mixture well.
3. Filter off the excess solid from the mixture using the filter paper and filter funnel.
4. Put the filtered mixture over the bunsen burner and evaporate the excess water from the mixture.
5. Allow the hot liquid to cool down and filter it again through the filter paper to get the pure gypsum.
valence electrons are the number of electrons in the outer shell. there can only be 8 electrons in the outer shell. The number of valence electrons can be used to determine how many bonds are needed.
For example: H2O
O (oxygen) has 6 valence electrons
H (hydrogen) has 1 valence electron
O needs 2 more electrons to be stable
H needs 1 more electron to be stable
O forms one bond with two H atoms to form H2O.
