An article about half-lives describes a parent isotope. What is a parent isotope? A. The isotope that forms from the radioactive decay of a less stable isotope.
B. The isotope that forms from the radioactive decay of a more stable isotope.
C. The isotope that undergoes radioactive decay to form a less stable isotope.
D. The isotope that undergoes radioactive decay to form a more stable isotope.

I think the answer is D.

D. The isotope that undergoes radioactive decay to form a more stable isotope.

Explanation:

In radioactivity, isotopes of an unstable atom disintegrates/decays into more stable ones accompanied with the emissions of certain particles e.g alpha, gamma and beta particles.

In this process, the isotope of the atom that undergoes radioactive decay to form a more stable isotope is known as the PARENT ISOTOPE while the more stable isotope that arises from the decay is called the DAUGHTER ISOTOPE.

(238, 92) Uranium → (234,90) Thorium + (4,2) Helium

In the above reaction, Uranium is the parent isotope because it decays into a more stable isotope (Thorium).

He's Right

Explanation:

i got it right

away from the curb

explanation:

the wheels would then hit the curb if it started to rolling, decreasing the chance of an accident.

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms