Modern atomic theory is, of course, a little more involved than Dalton's theory but the essence of Dalton's theory remains valid. Today we know that atoms can be destroyed via nuclear reactions but not by chemical reactions. Also, there are different kinds of atoms (differing by their masses) within an element that are known as "isotopes", but isotopes of an element have the same chemical properties.
Many heretofore unexplained chemical phenomena were quickly explained by Dalton with his theory. Dalton's theory quickly became the theoretical foundation in chemistry.
Answer:
the number of moles of the gas is 0.00174 mol.
Explanation:
Given;
temperature of the, T = 300 K
volume of the gas, V = 1.45 L
Pressure of the gas, P = 3.0 kPa
The number of moles of the gas is calculated using Ideal gas equation, as follows;
PV = nRT
Where;
n is number of moles of the gas
R is the ideal gas constant, = 8.315 L.kPa/mol.K
n = PV / RT
n = (3 x 1.45) / (8.315 x 300)
n = 0.00174 mol.
Therefore, the number of moles of the gas is 0.00174 mol.
Answer:
Nuclear energy produces radioactive waste
A major environmental concern related to nuclear power is the creation of radioactive wastes such as uranium mill tailings, spent (used) reactor fuel, and other radioactive wastes. These materials can remain radioactive and dangerous to human health for thousands of years.
Explanation:
Ionization energies are always negative quantities – (False)
Energy required to remove an outermost electron from gaseous atom is known as ionization energy. As energy is always required in ionization, therefore, ionization energy is always a positive quantity.
The third ionization energy is the energy needed to ionize three electrons from a neutral atom. (Ture)
1st ionization energy is the energy required to knock out outermost electron from neutral gaseous atom.
2nd ionization energy is the energy required to knock out second electron from neutral gaseous atom.
3rd ionization energy is the energy required to knock out third electron from neutral gaseous atom.
Oxygen has a larger first ionization energy than fluorine. (False)
Ionization energy increases when we move from left to right in a period. Fluorine comes after oxygen in 2nd period of the periodic table, so as per the trend, ionization energy of the fluorine is larger than oxygen.
The second ionization energy of an atom is always greater than its first ionization energy. (True)
Second ionization energy is always greater than first because of increased nuclear attraction after removing one electron.
