Shortcut Methods

Modern Physics:#

Integer Type:#

Question: What is the approximate number of protons in the nucleus of a gold atom?

Shortcut Method:

• The atomic number of gold (Au) is 79.
• The approximate number of protons is equal to the atomic number.

Solution: There are approximately 79 protons in the nucleus of a gold atom.

Question: How many valence electrons does a silicon atom have?

Shortcut Method:

• Silicon (Si) is in group 14 of the periodic table.
• Group 14 elements typically have 4 valence electrons.

Solution: A silicon atom has 4 valence electrons.

Decimal Type:#

Question: What is the approximate value of the speed of light in a vacuum?

Shortcut Method:

• The speed of light in a vacuum is approximately 3 x 10^8 meters per second.

Solution: The approximate value of the speed of light in a vacuum is 299,792,458 meters per second.

Question: What is the approximate value of the Planck constant?

Shortcut Method:

• The Planck constant is approximately 6.6 x 10^-34 joule-seconds.

Solution: The approximate value of the Planck constant is 6.626 x 10^-34 joule-seconds.

Multiple Choice Type:#

Question: Which of the following is not a fundamental particle of matter: protons, neutrons, or photons?

Shortcut Method:

• Photons are not fundamental particles of matter. They are quanta of light and belong to the category of bosons.

Solution: The correct answer is c. Photons.

Question: Which of the following is a vector quantity: displacement, speed, or temperature?

Shortcut Method:

• Displacement is a vector quantity because it has both magnitude and direction.

Solution: The correct answer is a. Displacement.

True/False Type:#

Question: True or false: All matter is made up of atoms.

Shortcut Method:

• All matter, whether solid, liquid, gas, plasma, or even the elusive dark matter, is composed of atoms.

Solution: True.

Question: True or false: The nucleus of an atom contains protons and electrons.

Shortcut Method:

• The nucleus of an atom contains protons and neutrons, not electrons.

Solution: False.

Fill in the Blank Type:#

Question: The _ _ of a wave is the number of waves that pass a given point in one second.

Shortcut Method:

• The frequency of a wave is the number of cycles that occur per second.

Solution: The frequency of a wave is the number of waves that pass a given point in one second.

Question: The _ _ of a wave is the distance between two consecutive peaks or troughs of the wave.

Shortcut Method:

• The wavelength of a wave is the distance between two consecutive peaks or troughs.

Solution: The wavelength of a wave is the distance between two consecutive peaks or troughs of the wave.