Question

20 40.078 ca calcium a. atomic mass b. atomic number c. the number available on earth d. element number 12. select the correct symbol fro the element. aluminum a. am b. au c. al d. sn 13. select the correct symbol for the element. sodium a. so b. na c. no d. sm 14. ca is the symbol for____. a. calcium b. carbon c. cobalt d. copper 15.the element that uses the symbol pb is__. a. platinum b. lithium c. phosphorous d. lead 16. magnesium is an example of____. a. a noble gas b. an alkaline metal c. a transition metal

Explanation:

1. Aluminum's chemical symbol is Al based on the standard chemical - element symbol system.
2. Sodium's chemical symbol is Na, which is derived from its Latin name 'natrium'.
3. Ca is the symbol for calcium as per the periodic - table notation.
4. Pb is the symbol for lead, from the Latin 'plumbum'.
5. Magnesium is an alkaline earth metal. It has two valence electrons and is found in Group 2 of the periodic table.

Answer:

1. c. Al
2. b. Na
3. a. Calcium
4. d. Lead
5. b. An alkaline metal