Question

phet - building an atom
link: https://phet.colorado.edu/en/simulation/build - an - atom
directions: in this assignment, your goal is to discover which particles affect the mass, name, and charge of an atom.

1. add protons, neutrons, and electrons to your atom. play around with adding different numbers of each.

which particles change the name of the atom?

1. build each of the atoms below in the simulation. what is the name of each of the following atoms?

a. an atom with 3 protons and 4 neutrons:
b. an atom with 2 protons and 4 neutrons:
c. an atom with 4 protons and 4 neutrons:
d. an atom with 2 protons and 3 neutrons:

1. play around with the simulation by adding and removing different numbers of protons, neutrons, and electrons in order to discover which particles affect the charge of an atom or ion.

a. which particle adds a positive charge to the atom?
b. which particle adds a negative charge to the atom?
c. which particle does not affect the charge?
d. what needs to be true in order for an atom to have a neutral charge?

1. play around with the simulation by adding and removing different numbers of protons, neutrons, and electrons in order to discover which particles affect the mass of an atom or ion.

a. which particle(s) affect the mass?
b. which particle(s) do not affect the mass?

Explanation:

Step1: Recall atomic - number concept

The atomic number (Z), which determines the name of the atom, is equal to the number of protons.

Step2: Identify atoms in part 2

a. With 3 protons, it is lithium.
b. With 2 protons, it is helium.
c. With 4 protons, it is beryllium.
d. With 2 protons, it is helium.

Step3: Recall charge - carrying particles

Protons have a positive charge, electrons have a negative charge, and neutrons have no charge. For a neutral atom, the number of protons equals the number of electrons.

Step4: Recall mass - contributing particles

Protons and neutrons contribute to the mass of an atom, while electrons have negligible mass compared to protons and neutrons.

Answer:

1. Protons change the name of the atom.

2.
a. Lithium
b. Helium
c. Beryllium
d. Helium
3.
a. Proton
b. Electron
c. Neutron
d. The number of protons must equal the number of electrons.
4.
a. Protons and neutrons
b. Electrons