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

Three alkali metals in group 1 are a. calcium, strontium, barium b. boron, aluminum, gallium c. sodium, potassium, rubidium d. fluorine, iodine, chlorine

Free answer. the treaty of versailles ended world war i, but some of the terms of the treaty contributed to the beginning of world war ii. which was one of the terms of the treaty? the answer would be "germany was forces to pay reparations to the allied countries.". i hope this .

He table below gives the atomic mass and relative abundance values for the three isotopes of element m. relative abundance (%) atomic mass (amu) 78.99 23.9850 10.00 24.9858 11.01 25.9826 what is the average atomic mass (in amu) of element m? 2.86 5.36 24.30 24.98