Review Quiz: Unit 2 10/10

Who is credited with discovering the electron?

• Marie Curie

• Albert Einstein

• Isaac Newton

• J.J. Thomson

Answer explanation

J.J. Thomson is credited with discovering the electron. This discovery was a significant milestone in the field of physics, as it led to the development of the atomic model. The other options, Marie Curie, Albert Einstein, and Isaac Newton, while notable scientists, did not discover the electron.

What is the charge of a proton?

• -1

• 0

• +1

• +2

Answer explanation

The charge of a proton is a fundamental property of matter. In the system of elementary charges, the proton has a charge of +1. This is because protons are positively charged particles. Therefore, the correct answer to the question is '+1'.

Who proposed the planetary model of the atom?

• Niels Bohr

• Max Planck

• Albert Einstein

• Ernest Rutherford

Answer explanation

The planetary model of the atom was proposed by Niels Bohr. This model, also known as the Bohr model, depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus, similar to planets revolving around the sun. This model was a significant step in the development of quantum mechanics.

The atomic number of an element is determined by the number of:

• protons

• neutrons

• electrons

• isotopes

Answer explanation

The atomic number of an element is determined by the number of protons in its nucleus. This is because the atomic number is defined as the number of protons in an atom, which distinguishes one element from another. The other options, neutrons, electrons, and isotopes, do not determine the atomic number of an element.

Who is known for the gold foil experiment that led to the discovery of the atomic nucleus?

• Albert Einstein

• Niels Bohr

• Marie Curie

• Ernest Rutherford

Answer explanation

Ernest Rutherford is known for the gold foil experiment that led to the discovery of the atomic nucleus. This experiment involved the deflection of alpha particles after they hit a thin gold foil. The results of this experiment led Rutherford to propose the existence of a small, dense, positively charged nucleus at the center of the atom.

Tags

NGSS.HS-PS1-8

What is the atomic number of oxygen?

• 12

• 10

• 6

• 8

Answer explanation

The atomic number of an element corresponds to the number of protons in its nucleus. In the case of oxygen, the atomic number is 8, which means it has 8 protons. Therefore, the correct answer to the question 'What is the atomic number of oxygen?' is '8'.

What is the symbol for the element with atomic number 1?

• O

• C

• H

• He

Answer explanation

The element with atomic number 1 is Hydrogen, which is denoted by the symbol 'H'. This is because the atomic number is equivalent to the number of protons in an atom, and Hydrogen has only one proton. Therefore, the correct answer to the question is 'H'.

Which subatomic particle has a mass of approximately 1 atomic mass unit (amu)?

• photon

• electron

• neutron

• proton

Answer explanation

The question asks about the subatomic particle with a mass of approximately 1 atomic mass unit (amu). The correct answer is 'proton'. Protons, found in the nucleus of an atom, have a mass close to 1 amu. Other options like photon and electron have negligible mass, while neutron also has a mass close to 1 amu but slightly more than a proton.

Who developed the periodic table ?

• Glenn T. Seaborg

• Albert Einstein

• Marie Curie

• Dmitri Mendeleev

Answer explanation

Dmitri Mendeleev is the scientist who developed the periodic table. He organized the elements based on their atomic weights and properties, which allowed for the prediction of new elements and their properties. The other options, Glenn T. Seaborg, Albert Einstein, and Marie Curie, made significant contributions to science, but they were not responsible for the development of the periodic table.

What is the maximum number of electrons that can occupy the first energy level (n = 1) of an atom?

• 6

• 8

• 2

• 4

Answer explanation

The maximum number of electrons that can occupy the first energy level (n = 1) of an atom is 2. This is because the first energy level has only one subshell (1s), which can hold up to 2 electrons. The other options are incorrect as they represent higher energy levels or incorrect electron configurations.