.When sodium atoms (Na) and chlorine atoms (Cl) join to make sodium chloride, or table salt, they form an ionic bond. Using this information, which pair of elements is most likely to form an ionic bond? potassium (K) and fluorine (F)
aluminum (Al) and aluminum (Al)
sulfur (S) and oxygen (O)
calcium (Ca) and neon (Ne)

potassium (K) and fluorine (F)

Explanation:

Potassium is an alkali metal just like sodium and fluorine is a halogen just like chlorine. A metal and nonmetal will often join to form an ionic compound.

Aluminum, if it was going to bond to itself, would be a metallic bond.

Sulfur and oxygen are both nonmetals and would form a covalent bond.

Calcium would not bond with neon as neon is a noble gas.

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.