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Answer :
According to the law of conservation of mass, the mass of reactants must be equal to the mass of products.
The balanced chemical reaction is,

As we know that the molar mass of magnesium is 24 g/mole, the molar mass of
is 32 g/mole and the molar mass of magnesium oxide is 40 g/mole.
From the given balanced reaction, we conclude that
As, 1 mole of magnesium react
mole of oxygen to give 1 mole of magnesium oxide.
So, the mass of Mg is 24 g, the mass of
and the mass of MgO is 40 g.
That means 24 g of Mg react with 16 g
to give 40 g of MgO.
Answer:
Potassium (K) has 19 protons.
Each neutral atom of Potassium has 19 electrons.
Explanation:
A) Potassium has 19 protons because the atomic number tells us how many protons are in an atom of the element. (The atomic number is the number above the element symbol. For example, the number above "K" is 19, which is the atomic number).
B) If an atom is neutral, this means that the atom has neutral energy. Protons give positive energy and electrons give negative energy. For the atom to be neutral, the atom must have balanced energy, therefore, making the number of electrons equal to the number of protons in a neutral atom.
Answer:
35.9%
Explanation:
The percent volume of the coffee solution can be calculated as follows:
% volume of coffee solution = volume of coffee/total volume of coffee solution × 100
According to this question, a cup of coffee has 71 mL of coffee and 127 mL of water. This means that, the total volume of coffee solution is;
71mL + 127mL = 198mL
% volume = 71/198 × 100
= 0.359 × 100
Percent volume of coffee solution = 35.9%
Oxygen- atomic number 8
1s² 2s² 2px² 2py¹ 2pz¹