Answer:
3 valence electrons
Explanation:
Because aluminum has three, that means three fluorines can bond. The make the formula AlF3, also known as aluminum trifluoride. Each of the fluorine atoms gets an electron to fill their shell, and the aluminum loses three, giving it a filled shell too (remember, aluminum has three extra electrons).
<span>The mass number given on
the periodic table is a weighted average of all the isotopes. You get the exact mass of
an isotope by adding the protons(atomic number) to the
number of neutrons in that isotope.</span>
Answer:
Explanation:
% yields = <u>experimental yields</u> / theoretical yields )x 100%
=( 302 ÷ 320 )x 100% = 94.4 %
% error = 100% - 94.37% 5.64%
or u can use this law :
% error =(theoretical value - experimental value )/ theoretical value) x 100%
( 320 - 302 )/ 320 ) x 100% = 5.64%
Answer is: Ka for the
monoprotic acid is 3.03·10⁻⁴.
<span>
Chemical reaction: HA(aq) </span>⇄ A⁻(aq) + H⁺<span>(aq).
c(monoprotic acid) = 0.0165 M.
pH = 2.68.
[A</span>⁻] = [H⁺] = 10∧(-2.68).<span>
[A</span>⁻]
= [H⁺] = 0.00209 M; equilibrium concentration.<span>
[HA] = 0.0165 M - 0.00209 M.
[HA] = 0.0144 M.
Ka = [A</span>⁻]·[H⁺] / [HA].<span>
Ka = (0.00209 M)² / 0.0144 M.
Ka = 0.000303 M = 3.03·10</span>⁻⁴<span> M.</span>
Answer:
the percent error expected from each of theses person's body:
in homes:
% E = 0.14267 %
in doctor's office:
% E = 0.257 %
Explanation:
- ° C = ( ° F - 32 ) * (5/9)
- % E = ( | true - exp | / true ) * 100
- body temp = 38.9 ° C = 102.02 ° F
thermometer used in homes:
⇒ T = 102.02 ° F +/- 0.1 ° F = 102.12 ° F ∧ 101,92 ° F
⇒ T = 102.12 ° F = 38.9555 ° C
⇒ % E = ( | 38.9 - 38.9555 | ) / 38.9 ) * 100 = 0.14267 %
in the doctor's oficce:
⇒ T = 38.9 ° C +/- 0.1 ° C = 39 ° C ∧ 38.8 ° C
⇒ % E = (( | 39 - 38.9 | ) / 38.9 ) * 100 = 0.257 %
