I'm confused what valence electrons are ? idk if they're the same as just regular electrons

Read "who built the pyramids? ”. leave this link open while you answer the questions throughout the assignment. give at least two reasons why some people claim the pyramids of giza were constructed by aliens.

What energy conversion occurs when a sling shot is used to shoot a rock across the room? (2 points) question 2 options: 1) stored mechanical energy is converted to mechanical energy. 2) stored mechanical energy is converted to radiant energy. 3) gravitational energy is converted to radiant energy. 4) gravitational energy is converted to mechanical energy.

Asample of sea water contains 6.28g of sodium chloride per litre of solution. how many milligrams of sodium chloride would be contained in 15.0ml of this solution?