PTS 2025 E1 Phy Science

An atom is electrically neutral because

• the numbers of protons and neutrons are equal.

• the numbers of protons and electrons are equal.

• neutrons balance the protons and electrons.

Which of the following does the nucleus contain?

• protons and electrons

• neutrons and electrons

• protons and neutrons

This model this model was the first to show a nucleus, consisting of protons and neutron. Electrons surround the nucleus but are not shown in distinct energy levels.

• The "Rutherford Model" of the atom

• The "Plum Pudding Model" of the atom

• The "Quantum Mechanical Model" of the atom

This model was developed after J.J. Thompson discovered electrons, a particle smaller than an atom. It shows electrons floating freely in a positive region.

• The "Plum Pudding Model" of the atom

• The "Rutherford Model" of the atom

• Democritus's model of the atom

• The "Quantum Mechanical Model" of the atom

In the atomic model nicknamed the "plum pudding" model, what do the plums represent?

• the nucleus

• the atom

• the electrons

• the positive material

The cathode-ray tube was used to discover the ____ by ____.

• electron by Thomson

• electron by Dalton

• proton by Thomson

• proton by Dalton

• electron by Rutherford

In order for an atom to be neutral what has to be true?

• The atom has more protons than neutrons
• The atom has more neutrons than protons
• The atom has the same number of protons and neutrons
• The atom has the same number of protons and electrons

Which subatomic particle has a negative charge in the atom?

• proton
• neutron
• electron
• quark

Most of the mass in an atom is made up of _____________________?

• protons and electrons
• protons and neutrons
• neutrons and electrons
• electrons and quarks

What does an orbital represent?

• the limits of the electron location

• the probability of the electron location

• the circular path that an electron travels around the nucleus

• the minimum distance between the electron and the nucleus