What is a subshell? explain why is it important.

What can the size and shape of a sand dune tell you about how it was formed?

What is the number of moles in 500L of He gas at STP

Why can't chemical changes be undone? Because of the chemical properties. Because Mark is an idiot. Because they need energy. Because new substances are formed.

A precipitation reaction is caused by mixing 100. mL of 0.25 M K2Cr2O7 solution with 100. mL of 0.25 M Pb (NO3) 2 solution. When the precipitate forms, it is filtered from the mixture.

Identify which of the concentration expressions can also be used to describe a solution with a concentration of 1 mg/mL of solute. Assume the density of the solution is 1.00 g/mL

A sample of hydrated calcium sulfate has a mass of 20.88 g. After it is heated, it has a mass of 16.51 g. What is the percentage by mass of water in the hydrate

All organisms need energy from food in order to survive. Plants produce their own food through photosynthesis. Animals must find external sources for food. Which of the following is true? A. Plants are autotrophs, and animals are heterotrophs. B.

What is effective nuclear charge of S2 - and S? Does the Zeff differs from ions and atoms of the same element.

You live 15.0 miles away from a shopping center and wish to calculate the distance in feet. There are 5280 ft in one mile

What is shielding effect?