Shelly biked 21 miles in 4 hours what is shelly's average speed in miles per hour at the same rate how many hours will it take shelly to bike 42 miles

shelly walks 5.25 miles per hour, it will take her 8 hours to walk 42 miles

Step-by-step explanation:

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.