An element has an atomic number of 30. how many protons and electrons are in a neutral atom of the element?

Concerning the 10.0 ml of 0.50 m nacl to 100 ml of solution: when a solution is diluted, does it change the number of moles dissolved?

Sodium sulfate dissolves as follows: na2so4(s) → 2na+(aq) + so42- (aq). how many moles of na2so4 are required to make 1.0 l of solution in which the na concentration is 0.10 m?

Imagine that you push on a large rock. at what point does your effort change the rock’s mechanical energy?