Since chromium has 24 as its atomic number (which mean that it has 24 proton and 24 electron in neutral ground state), the electron configuration for the chromium would be :
1s^2 , 2s^2 , 2p^6 , 3s^2, 3p^6 , 3d^5 , 4s^1
The chemical bonds in CH4 are all single bonds. C only can bond 4 times because it needs 8 electrons in it's outer shell and only has four right now. The bonds represented are all single bonds because there are two electrons present on each side of the carbon. Two electrons, in this case, equals one bond.
The atoms that the electrons leave behind become positive ions, and the interaction between such ions and valence electrons gives rise to the cohesive or binding force that holds the metallic crystal together
1 mole = 6.02 * 10^23 atoms. (avogadro's number)
5.75*10^24 atoms Al * ( 1 mol Al/ 6.02 * 10^23 atoms Al) = 9.55 mol
