1. The atomic number of an element is the total number of which particles in the
nucleus? (1 point).
neutrons
protons
electrons
protons and electrons

2. All atoms of the same element have the same _. (1 point)
A. number of neutrons
B. number of protons
C. mass numbers
D. mass

3. Isotopes of the same element have different _. (1 point)
A. positions on the periodic table
B.chemical behavior
C. atomic numbers
D. mass numbers

ad 1) - it's the number of protons. Incidentally, this is also the answer to the second question: the number of protons, counted as the atomic number is what distinguishes the elements.

Different isotopes of the same element have the same amount of protons but a different number of neutrons, which gives them a different atomic mass.

So: b), b), d)

Answer Link

sakshib sakshib · Answer 2 · 2019-08-22T11:02:12+02:00

1. The atomic number of an element is the total number of [tex]\boxed{{\mathbf{protons}}}[/tex] in the nucleus.

2. All atoms of the same element have the same [tex]\boxed{{\mathbf{\text{number of protons}}}}[/tex].

3. Isotopes of the same element have different [tex]\boxed{{\mathbf{\text{mass numbers}}}}[/tex] .

Further Explanation:

The smallest particle that is the building block of matter is known as an atom. Most of the space in an atom is empty and its mass is concentrated inside a small region called the nucleus.

Protons, electrons, and neutrons are the three subatomic particles that are present in the atom. Protons and neutrons are collectively called nucleons because these are located in the nucleus of the atom. Electrons revolve around the nucleus in definite orbits.

Atomic number is represented by Z and is equal to the number of protons present in the nucleus of the atom.

An atom is written as [tex]_{\text{Z}}^{\text{A}}{\text{X}}[/tex] , where A is the atomic mass or mass number, Z is the atomic number and X is the letter symbol of the element.

So the atomic number is equal to the number of protons in the nucleus of the atom.

The atoms of the same element have the same atomic number. Since we know the atomic number is equal to the number of protons present in the nucleus of the atom. So the atoms of the same element will also contain the same number of protons in them.

Atoms of the same element with same atomic number but different mass numbers are called isotopes. These have the same number of protons but the number of neutrons is different.

[tex]_{\mathbf{6}}^{{\mathbf{11}}}{\mathbf{C}}[/tex] and [tex]_{\mathbf{6}}^{{\mathbf{12}}}{\mathbf{C}}[/tex] are examples of isotopes. Both are the atoms of the same element carbon. The mass number of [tex]_6^{11}{\text{C}}[/tex] is 11 while that of [tex]_6^{12}{\text{C}}[/tex] is 12. But both of these have the same atomic number, i.e., 6.

So the isotopes of the same element have different mass numbers.

Learn more:

1. The number of significant figures: https://brainly.com/question/5222111

2. The main purpose of conducting experiments: https://brainly.com/question/5096428

Answer details:

Grade: High School

Subject: Chemistry

Chapter: Structure of the atom

Keywords: Atomic number, nucleus, protons, isotopes, same element, mass numbers, number of protons, atoms.