The answer to this question would be: <span>D. Magnesium
The </span><span>number of energy levels of aluminum is 3 which was why it was put on the 3rd row. The valence of calcium is 2 which is why it was put in the 2nd column. If you look at the periodic table, the answer should be clear that it was magnesium.</span>
<span>The equation for the dissociation of acetic acid is:
CH3CO2H(aq) + H2O(l) <---> H3O+(aq) + CH3CO2-(aq)
pH = 0.5(4.74 - lg(0.5)) = 2.52
so
[H^+] = 3.02*10^-3 M = 3.02 mM</span>
The partial pressure of water in 1 atm is 0.24 atm
Answer:
The correct statements that you must check are:
- The oxygen atom has a greater attraction for electrons than the hydrogen atom does (second statement).
- The electrons of the covalent bond are not shared equally between the hydrogen and oxygen atoms (fourth statement).
Explanation:
Electronegativity is the relative ability of an atom to pull the electrons in a covalent bond.
Hydrogen has an electronegativity of 2.20 and oxygen has 3.44. That means that oxygen attracts the electrons more strongly than hydrogen does (second statement).
As consequence, the electrons in the covalent bond H - O of water are not shared equally (fourth statement): the electron density will be higher around the O atoms.
Of course, this discards the statement telling that hydrogen atom attracts electrons much more strongly than the oxygen atom, and the statement telling that hydrogen and oxigen have same electronegativity.
Such difference in electron densities creates a dipole moment, so you discard the last statement (that the water dipole moment is equal to zero).
M(Ag)=12.5 g
Nₐ=6.022*10²³ mol⁻¹
n(Ag)=m(Ag)/M(Ag)
N=n(Ag)*Nₐ
N=Nₐm(Ag)/M(Ag)
N=6.022*10²³mol⁻¹*12.5g/107.868g/mol=6.97*10²²
A. 6.97 × 10²² atoms