First of all, as you seen the gases are noble which means that will not react with each other and in this case each gas create individual pressure.
P
= total pressure
P
= pressure of neon
P
= pressure of argon
P
= pressure of helium {which is required}
P
= P
+ P
+ P
1.25 = 0.68 + 0.35 + P
P
= 1.25 - [0.68 + 0.35] = 0.22 atm
<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:
1.14 M
Explanation:
grams/molar mass = ans. / volume
317/110.98=2.86/2.50=1.14 M
- Hope that helps! Please let me know if you need further explanation.
Answer:
B. They are clones of the parent plant
Explanation: