Question

sep develop models each helium atom has two protons. sketch models of helium - 3 and helium - 4, which have approximate masses of 3 amu and 4 amu, respectively. label and differentiate protons, neutrons, and electrons in your models.

Explanation:

Step1: Recall atomic - structure basics

Atomic mass (amu) = number of protons + number of neutrons. Electrons have negligible mass.

Step2: Calculate neutrons in helium - 3

For helium - 3 with atomic mass of 3 amu and 2 protons, number of neutrons = 3 - 2=1. And number of electrons = number of protons = 2 for a neutral atom.

Step3: Calculate neutrons in helium - 4

For helium - 4 with atomic mass of 4 amu and 2 protons, number of neutrons = 4 - 2 = 2. And number of electrons = 2 for a neutral atom.

Step4: Sketch the models

For helium - 3: Draw a nucleus with 2 protons (labeled as 'p') and 1 neutron (labeled as 'n'). Draw 2 electrons (labeled as 'e') in electron - shells around the nucleus.
For helium - 4: Draw a nucleus with 2 protons (labeled as 'p') and 2 neutrons (labeled as 'n'). Draw 2 electrons (labeled as 'e') in electron - shells around the nucleus.

Answer:

Sketch a model of helium - 3 with 2 protons, 1 neutron in the nucleus and 2 electrons in electron - shells. Sketch a model of helium - 4 with 2 protons, 2 neutrons in the nucleus and 2 electrons in electron - shells, with appropriate labels for protons, neutrons and electrons.