*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

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)

What is the molar mass of a gas that has density of 2.054 g/l

Jose and eric were given four samples in lab. the results of their analysis are shown in the table. based on the data they collected, which sample is most likely a metal?