An isotope, x, of a particular element has an atomic number of 8 and a mass number of 18. therefore:

a. x is an isotope of oxygen.
b. x has 10 neutrons per atom.
c. x has an atomic mass of 15.9994.
d. a and b.
e. a, b, and c.

D

Explanation:

Because the atomic number is 8, we can see that it is indeed an isotope of oxygen. If the mass number is 18, this means that the protons and neutrons added together = 18, so there are 10 neutrons. It does not have an atomic mass of 15.9994 like the element on the periodic table, however, as this is a confirmed isotope and not an average.

im not exactly sure but i think its b!

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.