Help me please will mark brainliest

D

Explanation:

Period is horizontal group, so left to right it does increase. Down the side they are numbered 1-7 and depending on valence electrons they can have different properties

A

Explanation:

Im pretty sure it's A. I MIGHT be wrong so dont quote me on this. THis is what the internet says:

"Atomic Radius. Atomic radii decrease from left to right across a period and increase from top to bottom along a group."

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.