What is the molar mass of na2co3? 60.0 g/mol 106.0 g/mol 118.0 g/mol 141.0 g/mol

Answer is: the molar mass od sodium carbonate (Na₂CO₃) is 106.0 g/mol.

M(Na₂CO₃) = 2 · Ar(Na) + Ar(C) + 3 · Ar(O).

M(Na₂CO₃) = 2 · 23 + 12 + 3 · 16 · g/mol.

M(Na₂CO₃) = 46 + 12 + 48 · g/mol.

M(Na₂CO₃) = 106 g/mol; molar mass of sodium carbonate.

Ar is relative atomic mass (the ratio of the average mass of atoms of a chemical element to one unified atomic mass unit) of an element.

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.