Question

which element is a transition metal?
lithium (li)
argon (ar)
strontium (sr)
germanium (ge)
rhenium (re)
question 12 (3 points)
how many valence electrons does an oxygen (o) atom have?
6
2
16
8
none are correct

Explanation:

• Transition metals are found in groups 3 - 12 of the periodic table. Rhenium (Re) is in group 7, a transition - metal group. Lithium is an alkali metal, argon is a noble gas, strontium is an alkaline - earth metal, and germanium is a metalloid.
• Oxygen has an atomic number of 8. Its electron configuration is 1s²2s²2p⁴. The electrons in the outermost shell (n = 2 in this case) are the valence electrons. There are 2 + 4 = 6 valence electrons.

Answer:

• Question 11: E. Rhenium (Re)
• Question 12: A. 6