Solutions for Numbergrid Puzzles. Just find the unique puzzle id for the puzzle you're working on and enter it below to find the solution. For Numbergrid puzzles, the unique ID is a series of eight numbers and/or letters, and is printed below each individual puzzle in the PDF. (i.e. SFA8229A).
The chemical bonding that holds the atoms of a metal together. This bond is formed from the attraction between mobile electrons and fixed, positively charged metallic atoms.
Covalent bond: A chemical bond formed when two atoms share one or more pairs of electrons with each other. Double bond: A covalent bond consisting of two pairs of electrons. Electronegativity: A numerical method for indicating the relative tendency of an atom to attract the electrons that make up a covalent bond.