Atomic Number and Mass Number Quiz

The atomic number of an atom is defined by the number of protons it has. It is determined by counting the number of protons in the nucleus of the atom.

The mass number of an atom is defined by the number of protons and neutrons it contains in its nucleus. It is calculated by adding the number of protons and neutrons together.

The atomic number of an element is represented with the symbol Z.

<p>The three subatomic particles present in atoms are protons, neutrons, and electrons.</p> Signup and view all the answers

<p>A proton has a positive charge of +1 and an atomic mass of 1 atomic mass unit.</p> Signup and view all the answers

<p>An electron has a negative charge of -1 and an atomic mass of essentially 0 atomic mass units.</p> Signup and view all the answers

<p>The atomic number is the number of protons an atom has.</p> Signup and view all the answers

<p>The atomic number can be found by looking at the whole number listed directly above or below the elemental symbol for the atom.</p> Signup and view all the answers

<p>The mass number is the sum of the protons and neutrons in an atom's nucleus.</p> Signup and view all the answers

<p>The formula for mass number is $A = ext{Protons} + ext{Neutrons}$.</p> Signup and view all the answers

<p>Isotopes are atoms of the same element with the same number of protons and different numbers of neutrons in their nuclei.</p> Signup and view all the answers

<p>The mass number of an atom can be determined by knowing the number of protons and neutrons in its nucleus.</p> Signup and view all the answers

<p>Atomic number and mass number both consider the number of protons present in a given element. The atomic number is simply the number of protons in the given element (Z), and the mass number is the number of protons + neutrons in an atom of the element (A). The relationship can be described as A = Z + number of neutrons.</p> Signup and view all the answers

<p>If one knows the atomic and mass numbers of a given atom, the number of neutrons can be calculated by rearranging the formula A = Z + number of neutrons into Number of neutrons = Z - A.</p> Signup and view all the answers

<p>The atomic number is a fundamental property of a given element and defines elements. It represents the number of protons in an atom. The mass number, on the other hand, is the number of protons + neutrons in an atom and is not a fundamental property. Different atoms of the same element can have different mass numbers due to varying numbers of neutrons.</p> Signup and view all the answers

<p>To determine the mass number of an atom, one must know the number of neutrons it has. The mass number is not automatically known based on its elemental identity. It can be estimated based on the known frequencies of isotopes for a given element.</p> Signup and view all the answers

<p>Isobars are atoms of different elements with the same atomic mass. They have different numbers of protons and neutrons that add up to the same total atomic mass. For example, carbon-14 and oxygen-14 are isobars. Carbon-14 has 6 protons and 8 neutrons, while oxygen-14 has 8 protons and 6 neutrons, but they both have a total of 14 nucleons.</p> Signup and view all the answers

<p>The mass number is the number of protons and neutrons in a single atom, while atomic mass is the weighted average of mass numbers of all atoms of the element. Atomic mass takes into account the relative frequencies of different isotopes of the element.</p> Signup and view all the answers

<p>The atomic mass of carbon is 12.011. It is calculated based on the relative frequencies of carbon-12, carbon-13, and carbon-14 isotopes in nature. Carbon-12 is the most common isotope of carbon.</p> Signup and view all the answers

<p>The atomic mass of an element can be found on the periodic table next to its element symbol.</p> Signup and view all the answers