If only an element's atomic number and weight are provided, what other atomic information can be determined for a neutral atom? (1 point)

Question

• only the valence electrons
• only the number of protons and electrons
• only the number of protons and neutrons
• the number of protons, electrons, and neutrons

Answer 1

If only an element's atomic number and weight are provided, the atomic information that can be determined for a neutral atom is:

the number of protons, electrons, and neutrons.

Here's how:

• Number of Protons: The atomic number is equal to the number of protons in the nucleus of the atom.
• Number of Electrons: In a neutral atom, the number of electrons is equal to the number of protons.
• Number of Neutrons: The number of neutrons can be determined by subtracting the atomic number from the atomic weight (rounded to the nearest whole number), since atomic weight is approximately the sum of protons and neutrons in the nucleus.

Thus, the correct choice is:

the number of protons, electrons, and neutrons.

Answer 2

What is true about stable isotopes? (1 point)
• A stable nucleus has a similar number of protons and neutrons.
Isotopes are always unstable because they are radioactive.
• Isotopes are naturally occurring in nature and always unstable.
Isotopes with more neutrons than protons are always stable.

Answer 3

The correct statement about stable isotopes is:

A stable nucleus has a similar number of protons and neutrons.

This statement is generally true for many stable isotopes, especially for those of lighter elements. While it is not universally true that stable nuclei must always have a similar number of protons and neutrons (as some stable isotopes can have significantly more neutrons than protons), this statement captures an important characteristic of many stable nuclei.

The other options are incorrect:

• Isotopes are always unstable because they are radioactive. (This is false; many isotopes are stable.)
• Isotopes are naturally occurring in nature and always unstable. (This is false; there are both stable and unstable isotopes in nature.)
• Isotopes with more neutrons than protons are always stable. (This is false; while some isotopes with more neutrons than protons can be stable, many are not.)

Therefore, the best choice is the first statement regarding stable nuclei having a similar number of protons and neutrons.