A helium nucleus has two protons and two neutrons. How many electrons does it take to equal the mass of a helium nucleus?

Verified step by step guidance

1. Step 1: Understand that the mass of a helium nucleus is made up of the mass of two protons and two neutrons. The mass of a proton is approximately 1.67 x 10^-27 kg and the mass of a neutron is approximately 1.67 x 10^-27 kg. Therefore, the total mass of a helium nucleus is approximately 4 x 1.67 x 10^-27 kg.
2. Step 2: Know that the mass of an electron is approximately 9.11 x 10^-31 kg.
3. Step 3: To find out how many electrons it would take to equal the mass of a helium nucleus, you would divide the mass of the helium nucleus by the mass of an electron.
4. Step 4: Set up the equation: (4 x 1.67 x 10^-27 kg) / (9.11 x 10^-31 kg) = number of electrons.
5. Step 5: Solve the equation to find the number of electrons. Remember, the number of electrons should be a whole number as you cannot have a fraction of an electron.

Key Concepts

Atomic Structure

An atom consists of a nucleus containing protons and neutrons, surrounded by electrons in orbitals. The number of protons defines the element, while neutrons contribute to the atomic mass. In helium, the nucleus has two protons and two neutrons, making it a stable and light element.

Mass of Subatomic Particles

The mass of subatomic particles varies, with protons and neutrons having a mass of approximately 1 atomic mass unit (amu) each, while electrons are significantly lighter, about 1/1836 of a proton's mass. This difference is crucial when comparing the mass of electrons to that of a nucleus.

Mass-Electron Equivalence

To determine how many electrons would equal the mass of a helium nucleus, one must compare the total mass of the nucleus (approximately 4 amu) to the mass of an electron. Since one electron has a mass of about 0.00055 amu, it would take a large number of electrons to match the mass of the helium nucleus.