Which elements have only one electron orbit or shell? a. hydrogen (h) and helium (he) b. helium (he) and lithium (li) c. krypton (kr) and iron (fe) d. hydrogen (h) and calcium (ca)

Write the formula for the following chemicals. 7. e. trinitrogen tetraoxide a calcium phosphate f. magnesium acetate b. potassium sulfide g nickel(iii) cyanide c carbon dioxide h. silver sulfate d. cobalt(ii) chloride

Is a chemical message sent by another individual.

What are several ways to reduce the effect of friction