Answer:
Phosphorus
Explanation:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction and electronegativity increases.
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus electronegativity decreases.
Silicon is present in group 4A and Phosphorus and Arsenic is present in group 5A thus electronegativity of silicon is less than Phosphorus and arsenic. Arsenic is present down to phosphorus thus its electronegativity will less than phosphorus.
P = 2.19
Si = 1.9
As = 2.18
<span>Isotopes are atoms of the same element with the same number of protons and same number of electrons but with <span>different
number of neutrons. They differ in the number of neutrons that is why
they also differ in mass numbers. Since they have the same number of
protons, they have the same atomic number.
For instance, when the
nucleus of the isotope with a 68.926 amu, there are 30 protons and 39
neutrons in the nucleus. The best example for this is Zn (zinc-69
isotope) and Ga (gallium-69 isotope) which has 68.926 amu and 68.925 amu
respectively.
</span></span>
Answer:
ΔH°f(C₈H₁₈(g)) = -210.9 kJ/mol
Explanation:
Let's consider the combustion of C₈H₁₈.
C₈H₁₈(g) + 25/2 O₂(g) ⟶ 8 CO₂(g) + 9 H₂O(g) ΔH°rxn = − 5113.3 kJ
We can calculate the standard enthalpy of formation of C₈H₁₈(g) using the following expression.
ΔH°rxn = 8 mol × ΔH°f(CO₂(g)) + 9 mol × ΔH°f(H₂O(g)) - 1 mol × ΔH°f(C₈H₁₈(g)) - 25/2 mol × ΔH°f(O₂(g))
1 mol × ΔH°f(C₈H₁₈(g)) = 8 mol × ΔH°f(CO₂(g)) + 9 mol × ΔH°f(H₂O(g)) - 25/2 mol × ΔH°f(O₂(g)) - ΔH°rxn
1 mol × ΔH°f(C₈H₁₈(g)) = 8 mol × (-393.5 kJ/mol) + 9 mol × (-241.8 kJ/mol) - 25/2 mol × 0 kJ/mol - (− 5113.3 kJ)
ΔH°f(C₈H₁₈(g)) = -210.9 kJ/mol
Answer: Solubility.
Explanation:
Solubility is defined as the maximum amount of solute dissolved per 100 g of the solvent at a certain fixed temperature to form a saturated solution.
STP condition is Standard Temperature and Pressure condition which is temperature of 273 K and pressure of 1 atm.
Thus the scientific term for "the number of grams of solute dissolved in 100 g of the solvent to form a saturated solution at STP" is called as Solubility.
The answer is Metalloids!