The alpha particle is the helium nucleus.
The mass of helium nucleus (⁴₂He) is 4u.
The mass of radioactive atom decreases by 4u. Look at the reaction below:
²²³₈₈Ra ---> ⁴₂He + ²¹⁹₈₆Rn
<u>Answer:</u>
Earth's axis and position around the sun.
<u>Explanation:</u>
Earth's tilted axis causes the seasons to change. Throughout the year, different parts of Earth acquire the Sun's most direct rays(Or heat) because of the orbital rotation of Earth. So, when the North Pole tilts toward the Sun, it's summer inside the Northern Hemisphere. And whilst the South Pole tilts towards the Sun, it is winter within the Northern Hemisphere and vise versa.
Letter C would be the correct answer
Answer:
it is made up of rays of varying frequencies