Help me pleaseee :((

Explain which group an element with the electron configuration 1s2 2s2 2p6 3s2 3p6 3d1 4s2 belongs to.

Which statement is true about hcl? (5 points) select one: a. it is a salt because it increases the concentration of metallic ions. b. it is a salt because it is formed by the reaction of an acid and a base. c. it is an acid because it increases the concentration of hydroxyl ions. d. it is an acid because it increases the concentration of hydronium ions.

Compare and contrast refraction of light and sound will give brainliest