Transverse wave, motion in which all points on a wave oscillate along paths at right angles to the direction of the wave's advance. Surface ripples on water, seismic S (secondary) waves, and electromagnetic (e.g., radio and light) waves are examples of transverse waves.
This is all no chemistry but the answer is C
Answer: Between 1 and 2.
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
............(1)
where,
a = amount of reactant left after n-half lives = 40
= Initial amount of the reactant = 100
n = number of half lives
Putting in the values we get:

taking log on both sides


Thus half-lives that have elapsed is between 1 and 2
<span>Since one is negative and one is positive they are held together by their electrostatic attraction to each other, much like how a north and south pole of a magnet attract.</span>
Magma- hot fluid or semifluid material below or within the earth's crust from which lava and other igneous rock is formed by cooling. Hope this helps!