<u>Answer:</u> The correct answer is 0.745 km
<u>Explanation:</u>
We are given:
A numerical value of 815 yards
To convert this into kilometers, we use the conversion factor:
1 km = 1093.6 yards
Converting the given value into kilometers, we get:

Hence, the correct answer is 0.745 km
Na-24 and Na-23 have the same number of atoms=11, different neutrons(13 and 12),different mass number(24 and 23)
<h3>Further explanation
</h3>
The elements in nature have several types of isotopes
Isotopes have the same number of protons and having a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
number of atoms = 11
mass number = 23
number of neutrons=23-11=12
number of atoms = 11
mass number = 24
number of neutrons=24-11=13
A. <span>principal energy level, sublevel, orbital, electron</span>
According to the octet rule, atoms tend to gain, lose, or share electrons until they are surrounded by__8__ valence electrons.
Since the volume is constant,
p1/t = p2/ t
210/120 = p2/150
p2= 262.5kpa