Can someone find the element group number
number of valence electrons
period number
for theses please

What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?

About 3% of the water on earth is freshest. only about 40% of that freshwater is available for human use. why is so much freshwater unavailable for human use?

Astudent states that 9.0 g of baking soda will form an unsaturated solution in 100 g of water. what do you need to know to decide whether this statement is correct? a. the temperature of the water and the molar mass of baking soda b. the percent by volume of the solution and the solubility of baking soda c. the temperature of the water and the solubility of baking soda at that temperature