B. All atoms of silver have the same atomic number but different numbers of neutrons in the nucleus.
Answer is: an oxybromate compound is KBrO₄ (x = 4).
ω(Br) = 43.66% ÷ 100%.
ω(Br) = 0.4366; mass percentage of bromine.
If we take 100 grams of compound:
m(Br) = ω(Br) · 100 g.
m(Br) = 0.4366 · 100 g.
m(Br) = 43.66 g; mass of bromine.
n(Br) = m(Br) ÷ M(Br).
n(Br) = 43.66 g ÷ 79.9 g/mol,
n(Br) = 0.55 mol; amoun of bromine.
From chemical formula (KBrOₓ), amount of potassium is equal to amount of bromine: n(Br) = n(K).
m(K) = 0.55 mol · 39.1 g/mol.
m(K) = 21.365 g; mass of potassium in the compound.
m(O) = 100 g - 21.365 g - 43.66 g.
m(O) =34.97 g; mass of oxygen.
n(O) = 34.97 g ÷ 16 g/mol.
n(O) = 2.185 mol.
n(K) : n(Br) : n(O) = 0.55 mol : 0.55 mol : 2.185 mol /÷ 0.55 mol.
n(K) : n(Br) : n(O) = 1 : 1 : 4.
Molar mass of 13c = 13 grams
number of moles = mass / molar mass
therefore,
number of moles = 7 / 13
To know the number of atoms in 7/13 moles, we simply multiply the number of moles by Avogadro's number as follows:
number of atoms = (7/13) x 6.022 x 10^23 = 3.2426 x 10^23 atoms
Answer:
Law of conservation of mass
Ernest Rutherford
Explanation:
The basic law of behavior of matter that states that "mass is neither created nor destroyed in a chemical reaction or physical change".
This is the law of conservation of mass. It is very essential in understanding most chemical reaction. Also, in quantitative analysis, this law is pivotal.
Ernest Rutherford was the scientist that stated that the nucleus is made up of positive charge. It was not until James Chadwick in 1932 discovered the neutron that we had an understanding of this nuclear component.
Rutherford surmised from his experiment that because most the alpha particles passed through the thin Gold foil and just a tiny fraction was deflected back, the atom is made is made up of small nucleus that is positively charged.
