What elements has a complete outermost energy level and is found in the 4th period

A nitrogen atom has five valence electrons. The Lewis structure shows how a nitrogen atom bonds with three hydrogen atoms to form an ammonia molecule, NH3. How many valence electrons does the nitrogen atom have in this ammonia molecule?

A motorist travels a distance of 406km. during a 7 hour period. what was the average speed?

How many grams of solute are present in 645 mL of 0.410 M KBr?

In relation to chemical solutions, which term does not express a degree of saturation? A: unsaturated B: saturated C: supersaturated D: oversaturated

The molar mass of lif is 25.94 g/mol. how many moles of lif are present in 10.37 g?

A specific, electrically neutral atom of boron has 5 protons, 5 electrons, and 6 neutrons. what is the mass number of this atom of boron? 6 5 11 16

When does hail happen?

For the reaction, calculate how many moles of the product form when 0.012 mol of O2 completely reacts. Assume that there is more than enough of the other reactant. 4Al (s) + 3O2 (g) →2Al2O3 (s) Express your answer using two significant figures.

Nuclei with too many or too few neutrons are?

Be sure to answer all parts. Enter the formula for potassium dihydrogen phosphate and determine its molecular (formula) mass.