*40 IF YOU ANSWER CORRECTLY & ADDED BRAINIEST* *IF COMMENT IS IRRELVANT, YOUR ACCOUNT WILL BE REPORTED*

1.) An electron configuration of 2-7-6 represents the atom of...
A.) phosphorus and is in the ground state
B.) phosphorus and is in the excited state
C.) potassium and is in the ground state
D.) potassium and is in the excited state

2.) An atom contains three valence electrons. This atom could be *
A.) sodium
B.) magnesium
C.) aluminum
D.) silicon

In the reaction between a crushed antacid tablet and vinegar what gas is emitted

What is the mass of 0.46 mol of mgcl2

Tooth enamel consists mainly of the mineral calcium hydroxyapatite, ca_10(po_4)_6(oh)_2. trace elements in teeth of archaeological specimens provide anthropologist with clues about diet and diseases of ancient people. students at hamline university measured strontium in enamel from extracted wisdom teeth by atomic absorption spectroscopy. solutions with a constant total volume of 10.0 ml contained 0.726 mg of dissolved tooth enamel plus variable concentrations of added sr. added sr find the concentration of sr in the 10 ml sample solution in parts per billion = ng/ml. find the concentration of sr in tooth enamel in parts per million = mu g/g.