Question

a balanced chemical equation has the same number of each type of ______ on both sides of the arrow.
molecules
atoms
compounds
ions
what holds the atoms together in a covalent compound?
they share electrons.
they give away electrons.
they take electrons.
they share protons.
which of the following is the proper electron dot diagram for nacl?
a) na :cl:
b) na+ :cl:-
c) na+ cl-
d) na+ :cl:

Explanation:

1. In a balanced chemical equation, the law of conservation of mass is obeyed by having the same number of each type of atom on both sides of the arrow. Molecules, compounds, and ions can vary in number depending on the stoichiometry of the reaction, but atoms are conserved.
2. In a covalent compound, atoms share electrons to achieve a stable electron - configuration. Giving away or taking electrons is characteristic of ionic bonding, and protons are not shared in chemical bonding.
3. Sodium chloride (NaCl) is an ionic compound. Sodium (Na) loses one electron to form a sodium ion ($Na^+$) and chlorine (Cl) gains one electron to form a chloride ion ($Cl^-$). The electron - dot diagram for NaCl shows the sodium ion as a simple ion symbol with a positive charge and the chloride ion with its full valence - shell electrons represented by dots and a negative charge.

Answer:

1. B. Atoms
2. A. They share electrons.
3. b) $[Na]^+[:\ddot{Cl}:]^-$