Please help me with this question... I can't seem to understand

Step-by-step explanation:

To calculate the horizontal distance d we use cosine

cos ∅ = adjacent / hypotenuse

From the question

d is the adjacent

the hypotenuse is 145m

So we have

cos 55 = d / 145

d = 145 cos 55

d = 83.16

d is 83.2 meters to 3 significant figures

Hope this helps you

the answer is: d) o, f, and kr.

atomic radius of bromine (br) is 114 pm.

atomic radius of oxygen (o) is 73 pm.

atomic radius of fluorine (f) is 72 pm.

atomic radius of krypron (kr) is 112 pm.

the atomic radius of a chemical element is a measure of the size of its atom.

the atomic radius varies with increasing atomic number, but usually increases because of increasing of number of electrons.

the atomic radius decreases across the periods because an increasing number of protons, because greater attraction between the protons and electrons.