in the gold foil experiment, more than 99% of the alpha particles passed thorough the gold foil with little or no deflection. As a result, Rutherford concluded that most of the volume of each gold atom was empty space.

Protons and neutrons are located int he nucleus of any atom, carbon included. Electrons are located outside the nucleus.

The proton is the only positive particle in an atom. It is located in the nucleus. Neutrons are neutral, with a zero charge also located in the nucleus. Electrons are negatively charged and are located outside the nucleus in orbitals.

A neutron has approximately the same mass as a proton.

As electrons in an excited state move to a lower energy levels, the release of energy in the form of electromagnetic radiation (light).

Isotopes of the same element must have the same atomic number, i.e., protons.

Use the Periodic Table of elements. All Group 13 elements have 3 valance electrons. Lewis electron-dot diagrams display only the valance electrons of the atom.

Valance electrons are found in the outer most shell of an atom of or ion. Refer to the Periodic Table of Elements. The ground state electron configuration of calcium (Ca, atomic number 20) is 2-8-8-2. There are 2 electrons in the outer most shell of this atom in the ground state.

The nuclei of all atoms (with the exception of H-1_ contains protons and neutrons. (H-1 contains no neutrons only one proton).

The physicist J.J. Thomson used cathode rays to identify the properties of the negative particles known as electrons.

The average atomic mass of an element is calculated by determining the weighted average of all the element’s naturally occurring isotopes. The most abundant, naturally occurring isotopes have the greatest effect on the value of the average atomic mass.

The isotopes K-37 and K-42 are isotopes of the same element, potassium. Each element has a unique bright-line spectrum. Therefore, K-37 and K-42 will have the same bright-line spectrum.

An element is defined by the number of protons contained in each atom of the element, which is its atomic number. Refer to the Periodic table of elements. The element carbon (C) has an atomic number of 6.

An atom of O-17 contains 8 protons, 9 neutrons, and 8 electrons. The masses of these subatomic particles in decreasing order are  neutrons> protons> electrons. Since the most massive particles (the neutron) is present in the greatest quantity (9), it follows that neutrons contribute most to the mass composition of O-17.