The two notations that represent isotopes of the same element is the one that represented in option 1
The lower number is the number of protons while the upper number is the atomic weight
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Answer:
An atom of Al which has 13 protons and 10 electrons is Al cation (Al⁺³)
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other.
For example,
Al atom has 13 protons and 13 electrons. The number of positive and negative charge is equal thus it will be neutral atom.
While the atom of Al which have 13 proton and 10 electron is not neutral. The positive charge is greater than negative by 3. Which means 3 electrons are lose by Al atom and form cation "Al⁺³".
Thus an atom of Al which has 13 protons and 10 electrons is Al cation (Al⁺³)
Answer:
3.75 g.
Explanation:
<em>mass percent is the ratio of the mass of the solute to the mass of the solution multiplied by 100.</em>
<em />
<em>mass % = (mass of solute/mass of solution) x 100.</em>
<em></em>
mass of calcium nitrite = ??? g,
mass of the solution = 25.0 g.
∴ mass % = (mass of solute/mass of solution) x 100
<em></em>
<em>∴ mass of solute (calcium nitrite) = (mass %)(mass of solution)/100</em> = (15.0 %)(25.0 g)/100 = <em>3.75 g.</em>
The molarity is calculated using the following rule:
molarity = number of moles of solvent / volume of solution (in liters)
We have the volume of solution = 250 ml = 0.25 liters and the molarity = 3 m
Substituting in the equation, we get:
3 = number of moles / 0.25
number of moles = 3 x 0.25 = 0.75 moles
1. 1 M , 2 M , 1 M
2. 10 mol , 0.1 mol , 0.5 mol
3. 0.5 L , 6.6 L , 5/21 L
M = mol/L
