Which statement is true of unstable isotopes?

a)nuclei of light elements are very unstable. b)the nuclei of atoms that are the most unstable have proton to neutron ratios of 1 to 1.c)an unstable atom is an atom that has enough binding energy to hold the nucleus together permanently. d)an unstable isotope is one that undergoes spontaneous nuclear decay and is referred to as a radioisotope.

The correct answer is Option D.

Explanation:

Unstable isotopes are defined as the isotopes which have excess of neutrons as compared to the stable form of the nucleus of an atom.

These isotopes attain stability by undergoing a spontaneous nuclear decay. The isotopes which are unstable have another name and are known as radioactive isotopes or radioisotopes.

These isotopes undergoes decay by 4 processes: Alpha decay, beta decay, gamma emission and positron decay.

Hence, the correct answer is option D.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

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