Rank these elements from smallest to largest atomic radii: zinc, calcium, radium, and bromine. Select one:
O a. calcium, radium, zinc, bromine
O b. calcium, zinc, bromine, radium
c. bromine, zinc, calcium, radium
d. bromine, zinc, radium, calcium

The correct option is;

c. Bromine, zinc, calcium, radium

Explanation:

The atomic radii of the elements as arranged in the periodic table decreases across the period and increases down the groups

The location of each of the elements are;

Zinc: Period 4, Group 12

Calcium: Period 4, Group 2

Radium: Period 7, Group 2

Bromine: Period 4, Group 17

Therefore, the element with the largest atomic radius = Radium

The element with the smallest atomic radius = Bromine

Calcium comes before zinc on period 4, therefore, the atomic radius of calcium is larger than that of zinc

The rank of the elements from smallest to largest atomic radius is therefore;

Bromine, zinc, calcium, radium.

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles

i believe that it is a exoplanet