`1s22s22p63s2 Which diagram shows the correct distribution of electrons in the electron shells of a magnesium atom?

When determining the shape of a molecule, it is important to draw a lewis dot structure first in order to see the total number a. electrons within the moleculeb. bonding and unshared pairs around central atomc. unshared pair within the molecule( i really need it )

Use the periodic table to determine how many grams of oxygen would be required to react completely with 859.0 g c2h2

Concentrations expressed as a percent by mass are useful when the solute is a a. liquid b. gas c. solid