Which element has 7 valence electrons and 3 electron shells

1) which of the following is the best example of a physical change? a) sugar dissolving in tea b) firefly glowing 2) in the combustion of ethane, what is/are the reactants? c2h6 + o2 ==> co2 + h2o a) c2h6 and o2 b) co2 and c2h6

Question 3(multiple choice worth 4 points) (04.04 lc) what does it mean when an element is reduced? it empties a valance shell, reducing its atomic radius. it gains electrons, reducing its overall charge. it increases electronegativity, reducing its ability to bond. it loses electrons, reducing its electron number.

Astudent states that 9.0 g of baking soda will form an unsaturated solution in 100 g of water. what do you need to know to decide whether this statement is correct? a. the temperature of the water and the molar mass of baking soda b. the percent by volume of the solution and the solubility of baking soda c. the temperature of the water and the solubility of baking soda at that temperature