Which group of elements contains a metalloid?
(1) group 8 (3) group 16
(2) group 2 (4) group 18

Write the symbol for every chemical element that has atomic number greater than 3 and atomic mass less than 12.0 u.

Acompound has a molar mass of 92.02 grams/mole, and its percent composition is 30.4% nitrogen (n) and 69.6% oxygen (o). what is its molecular formula? a. n2o4 b. no2 c. n2o d. n4o2

What was bohr’s contribution to the planetary model