Answer: Within each element square, information on the element's symbol, atomic number, atomic mass, electronegativity, electron configuration, and valence numbers can be found. At the bottom of the periodic table is a two row block of elements that contain the lanthanoids and actinides.
a is the correct answer .
2.4 × 10^24
Sodium chloride is made from one sodium atom and one chlorine atom:
Sodium has a charge of +1, or just +.
Chlorine has a charge of -1, or just -.
These balance out.
