Use the periodic table to identify the number of core electrons and the number of valence electrons in each case below. Potassium (K): 1s22s22p63s23p64s1

18
core electrons
1
valence electrons
Iron (Fe): [Ar]4s23d6

18
core electrons
8
valence electrons
Argon (Ar): [Ne]3s23p6

10
core electrons
8
valence electrons
Magnesium (Mg): 1s22s22p63s2

10
core electrons
2
valence electrons

When svante arrhenius first proposed his acid-base theory, he was a doctoral candidate. his professors thought his ideas were unfounded. within a decade, the arrhenius theory of acid-base was widely accepted and praised within the scientific world. arrhenius defined acids as compounds having ionizable hydrogen and bases as compounds with ionizable a) barium. b) hydronium. c) hydroxide. d) oxygen.

Which position represents spring in the southern hemisphere? a) b) c) d)

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.