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)

How have traits been accumulated in plants and animal over the centuries

Which of the following claims are based on scientific evidence? Red sky at night sailors' delight, red sky in morning sailors take warning. Touching toads gives you warts.

Predict the geometry about each interior atom in acetic acid:

At STP fluorine is a gas and iodine is a solid. This observation can be explained by the fact that fluorine has

Write the balance equation for Zn (NO3) 2 (aq) + NaOH (aq) 

An aqueous solution is made from a molecular compound rather than from an ionic compound. If some ions are present in solution, which best describes the solute? A. a weak electrolyte B. a nonelectrolyte C. a strong electrolyte D.

Which of the following measures the radiation given off by atoms per second?

What is the name of the outermost layer that forms a boundary around the outside of each cell

What does an ionic compound form?

How many electrons in an atom could have these sets of quantum numbers n=7 l=3 ml=-1?