Answer:
C) 1 and 3
Explanation:
A period in the periodic table is a row of chemical elements. All elements in a row have the same number of electron shells. ... Arranged this way, groups of elements in the same column have similar chemical and physical properties, reflecting the periodic law.
Answer:
They can be dated using radioactive carbon. But for rocks older than 50 thousand years they look for layers of igneous rock or volcanic ash above and Bellow the layer of rock/fossil.
Hydrogen oxygen argon carbon hope you get a 100
The answer to this question is 1s^2.
