How many of the elements on the current periodic table can contain orbitals having n = 1 as their principal quantum number? enter a numerical value.

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit

Select the statement that describe chemical properties a. antacid tablets neutralize stomach acid b. helium is the lightest monatomic element c. water freezes at 0 celsius d. mercury is liquid at room temperature