Part 1: Name two elements that have the same properties as potassium (K). (4 points) Part 2: Determine the number of protons, electrons, and neutrons present in an atom of magnesium (Mg). Explain how you determined your answer using complete sentences. (6 points)

Part 1: Sodium and Rubidium.

Part 2:

Protons = 12

reason: protons are equal to the atomic number of an atom. For Magnesium, atomic number is 12.

Neutrons:

reason: neutrons is given by formula:

where mass number of magnesium is 24.

electrons: = 12 electrons

reason: Magnesium atom has electrons summing up to 12

chemical properties are the characteristic of matter which can only be observed by changing the chemical identity of a sample like flammability reactivity and toxicity.

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.