:

read the given expression.

x = atomic number − number of core electrons

which of the following explains the identity of x and its trends down a group?
x is the effective nuclear charge, and it remains constant down a group.
x is the screening constant, and it remains constant down a group.
x is the effective nuclear charge, and it increases down a group.
x is the screening constant, and it increases down a group.

X is the effective nuclear charge, and it remains constant down a group.

X is the screening constant, and it remains constant down a group.

Explanation:

It makes more sense and the core electrons are known as the shielding electrons, or screening constant. Usually when something is constant it remains consistent/unwavering.

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

"hydrogen bonding is the attraction of h atoms in the water molecule (slight + charge) to o atoms in a neighboring water molecule (slight - charge); it is a weak interatomic force. but it is still strong enough to the water molecules "stick" together."