<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.
Kc = concentrations of product / concentrations of reactant
Kc = [Br₂] [Cl₂]₃ / [BrCl₃]₂
What is the equilibrium constant?
The relationship between a reaction's products and reactants with regard to a certain unit is expressed by the equilibrium constant(K) This article introduces the mathematics needed to determine the partial pressure equilibrium constant as well as how to formulate expressions for equilibrium constants. By allowing a single reaction to reach equilibrium and then measuring the concentrations of each chemical participating in that reaction, one can determine the numerical value of an equilibrium constant. it is the ratio of product concentrations to reactant concentrations. The equilibrium constant for a given reaction is unaffected by the initial concentrations because the concentrations are measured at equilibrium.
To learn more about the equilibrium constant, visit:
brainly.com/question/19340344
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Answer:
M of Al=33.09g or 0.0331kg
Explanation:
Heat Energy= specific heat*mass*change in temperature
H=M*C*T
make M subject of the formula
M=H/CT
M=685J/0.90J/g°C*(45°C-22°C)
M=685J/0.90J/g°C*23°C
M=685J/20.7J/g
M=33.09g or 0.0331kg
Answer:
=> 2.8554 g/mL
Explanation:
To determine the formula to use in solving such a problem, you have to consider what you have been given.
We have;
mass (m) = 16.59 g
Volume (v) = 5.81 mL
From our question, we are to determine the density (rho) of the rock.
The formula:

Substitute the values into the formula:

= 2.8554 g/mL
Therefore, the density (rho) of the rock is 2.8554 g/mL.