Explanation:
Moles=mass/molar mass
moles × molar mass = mass
0.206 x 119= mass
Mass= 24. 51grams
<u>Answer: </u>The correct statement is X is the effective nuclear charge, and it increases across a period.
<u>Explanation:</u>
We are given that:
X = number of protons − number of core electrons
Effective nuclear charge is defined as the actual nuclear charge (Z = number of protons) minus the screening effect caused by the electrons present between nucleus and valence electrons. These electrons are the core electrons.
The formula used for the calculation of effective nuclear charge given by Slater is:

where,
= effective nuclear charge
Z = atomic number or actual nuclear charge or number of protons
= Screening constant
The effective nuclear charge increases as we go from left to right in a period because nuclear charge increases with no effective increase in screening constant.
Hence, the correct answer is X is the effective nuclear charge, and it increases across a period.
Answer:
for one mole of C2H6 there are 7/2 mole of O2 required. so for4. 50 moles you require 4.50 x 7/2 = 15.75 moles of O2.
Explanation:
i hope it's helpful
Answer:
Enzyme
Explanation:
An enzyme is an organic catalyst that speeds up a reaction but can be recovered unchanged.
Human lactase consists of 4092 amino acid groups and has a molar mass of about 280 000 u, so it has a complex structure.