Answer:
The unit that is a radical among the options is;
a. NH₄⁺
Explanation:
A radical is an atom, group of atoms molecule or ion that contains an electron that is unpaired. The presence of the unpaired electrons make radical very reactive as such most radicals enter into reactions with other species or with themselves to form new compounds making them not last long.
Radicals are also known as free radicals. Examples of radicals includes; Ammonium ion, NH₄⁺
Nitrate ion NO₃⁻ (From a salt)
Hydroxide ion OH⁻ (From a base)
Sulphate ion SO₄²⁺ (From an acid)
All of which are formed in aqueous solution of acids, salts and bases.
m = Mass of the refrigerator to be moved to third floor = 136 kg
g = Acceleration due to gravity by earth on the refrigerator being moved = 9.8 m/s²
h = Height to which the refrigerator is moved = 8 m
W = Work done in lifting the object
Work done in lifting the object is same as the gravitational potential energy gained by the refrigerator. hence
Work done = Gravitation potential energy of refrigerator
W = m g h
inserting the values
W = (136) (9.8) (8)
W = 10662.4 J
The equator has no continental borders.
Before the skydiver opens the parachute, his velocity would be increasing greatly as much as 9.8 m/s². Opening the parachute would increase the surface area to which air may cause resistance. The skydiver then reaches his terminal velocity.