1. 4 electrons
2. Ernest Rutherford
3. Discovered the existence of a center of atom
4. 17 protons
Answer:
Approximately 53.3 %.
Explanation:
Molar mass of C2H4O2
= 2 * 12.011 + 4 * 1.008 + 2 * 15.999
= 60.052
% oxygen = (31.998* 100) / 60.052 = 53.28 %
Answer : The more abundant isotope is, Li isotope-7
Explanation :
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
For Li isotope-7 :
Mass of Li isotope-7 = 7 amu
Fractional abundance of Li isotope-7 = 92.5 %
For Li isotope-6 :
Mass of Li isotope-6 = 6 amu
Fractional abundance of Li isotope-6 = 7.5 %
Average atomic mass of Li = 6.941 amu
As we know that the more abundant isotope is that whose percentage abundant will be more and atomic mass of isotope will be near to average atomic mass of isotope.
From this we conclude that, the percentage abundant of Li isotope-7 is more and their atomic mass is near to average atomic mass.
Hence, the more abundant isotope is, Li isotope-7
Moles of the unknown gas in the flask : 0.216
<h3>Further explanation</h3>
The gas equation can be written
where
P = pressure, atm
V = volume, liter
n = number of moles
R = gas constant = 0.08206 L.atm / mol K
T = temperature, Kelvin
V=5 L
P = 1.05 atm
T = 296 K
Mass =70 ( Mass of protons=1 ,Mass of neutrons =1, Mass of electron =0.0005(can be ignored))
Therefore, 40 +30=70
Charge= -2 ( it is taking in/attracting electrons to its shell) base on the proton number you are able to identify if it is attracting or releasing an electron, if the electron number is more than proton number then it is attracting therefore resulting in a negative charge vice versa for releasing an electron.
