Part 1: Potassium, and Rubidium.
Part 2: Calcium has 20 protons and 20 electrons because the atomic number for calcium is 20 and that determines how many protons there are and in an atom, the number of protons is the same number of electrons. Calcium has about 20 neutrons. I got the number of Neutrons by subtracting the mass number(40.078) and the atomic number(20), I got 20.078. Round to the nearest whole number because you cannot have half or partial neutron. So, Calcium has 20 protons, 20 electrons, and 20 neutrons,
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The answer is c.) Rutherford model
Carbon dioxide. <span>Cellular respiration is this process in which oxygen and glucose are used to create ATP, carbon dioxide, and water. ATP, carbon dioxide, and water are all products of this process because they are what is created. Carbon dioxide is released as a gas when you exhale.</span>
Answer:
A. The increase in the mass of the magnesium oxide was due to oxygen atoms in the air.
Explanation:
Burning occurs in the presence of oxygen. A chemical combination occurs between Mg and O in that the atom of magnesium attracts one another.
Mg + O₂ → MgO
Starting with the magnesium, on reacting with oxygen a new compound forms. This is why there is mass increase in the MgO compared to the starting material.