A covalent bond is formed by: loss of electrons between atoms
sharing of electrons between atoms
gain of electrons between atoms
valence electron shells overlaping, forming a "sea of electrons"

Achange in the number of neutrons in an atom will change an blank . when the number of protons changes in an atom, a new element will form.

Read the chemical equation. 2c2h2 + 5o2 → 4co2 + 2h2o which of the following statements would be correct if one mole of c2h2 was used in this reaction? one mole of oxygen was used in this reaction. five moles of oxygen were used in this reaction. four moles of carbon dioxide were produced from this reaction. two moles of carbon dioxide were produced from this reaction.

What element has similar physical and chemical properties as boron.