Which pair of atoms has the most polar bond?
(1) h−br
(2) h−cl
(3) i−br
(4) i−cl

option (2) H - Cl

Explanation:

1) The polar character of a covalent bond is defined by the difference in the electronegativities of the atoms. The higher the diffrerence the greater the polar character of the bond.

2) The electronegativities of the elements are found in tables.

These are the electronegativities of the four elements of the question:

H: 2.20 ← lowest

I: 2.66

Br: 2.96

Cl: 3.16 ← highest

3) Since Cl has the greatest electronegativity of the four elements, and H has the lowest one, it is the bond H - Cl which will have the greatest difference of electronegativities, and it is the most polar bond.

b. atoms in metallic solids are not arranged in a regular pattern

explanation:

calculate how many grams of ammonia can be produced from 4.21 grams of

n2 + 3h2 = 2nh3

my answer:

25.0g n2 x (1 mol/ 28.0gn2) x (2 mol nh3/ 1 mol n2) x (17.0g nh3/ 1 molnh3) = 30.36g n2

25.0g h2 x (1 mol h2/ 2.00g h2) x (2 mol nh3/ 3 mol h2) x (17.0g nh3/ 1 mol nh3) = 141.67g h2

lr = n2