If you have to pick 3 answers then B, C, and D but if you pick only 1 answer then pick D
Explanation:
a. A grocery bag as you lift it up
b. A crane moving dirt......
d. A crate as you push it along the floor
Always, whether we notice it or not. It's a law of nature.
Density + mass / volume = 42 / 22 = 1.909 kg / m^3 ( to the nearest thousandth)
Answer:
The correct answer is option A: they are isotopes.
Explanation:
From atom X we know that the number of protons is 7 and the number of neutrons is 7 and from atom Z we know that the number of protons is 7 and the number of neutrons is 8.
Since the number of protons of atom X and atom Z is the same, we have that atom X and atom Z is the same element. The difference in the number of neutrons tells us that atom X and atom Z are isotopes. Remember that an isotope is one element that has atoms with different numbers of neutrons.
The mass number is given by:
Where <em>n</em> is the number of neutrons and <em>p </em>is the number of protons.
For atom X and atom Z we have:

Hence, they have a different mass number.
We know that the element with 7 protons is nitrogen. The first isotope is
and the second isotope is
. Both isotopes are stables (they are not radioactive).
Therefore, the correct answer is option A: they are isotopes.
I hope it helps you!