Find the valence electron for helium

A spherical balloon contains a positively charged object at its center. as the balloon is inflated to a greater volume while the charged object remains at the center, what does the electric potential at the surface of the balloon do?

Carlos is making phosphorous trichloride using the equation below. He adds 15 g of phosphorus. 2P + 3Cl2 → 2PCl3 How much chlorine would be found in the product

An irrelgular object with a mass of 118g displaces 25ml of water when placed in a graduated cylinder. What is the density

The concentration of sodium hydroxide is 1.0 M and the concentration of crystal violet is 1.00 x 10-5 M. Identify the limiting reagent and calculate how much of the excess reagent remains after the reaction runs to completion

3H2+N2->2NH3 How many grams of ammonia are created from 5.00 mol of hydrogen

What volume will 0.710 moles of nitrogen gas occupy at STP?

4) Acompound has an empirical formula of Na2co3, and a molar mass of 3.18g/mol. Find its molecular formula.

How many molecules of glucose, C6H12O6, can be "burned" biologically when 283.2 grams of oxygen is a available?

Why does acids that has been accidentally spilled on a book cause the colour of the book cover and the ink to change?

How many moles of H2O will be required to make 19.2 moles of O2