Answer:
A. Pu -239
Explanation:
An isotope is an element with the same atomic number but different mass number. most isotope are unstable, having short half life.
Curium-242 is an isotope produced when Plutonium 239 is bombarded by an alpha particle. This reaction between Plutonium 239 and alpha particle gives curium-242, neutron and a high amount of energy as the products.
Curium oxidizes easily, and it is a dangerous metal which can cause cancer initiation when absorbed by biological materials e.g bones or tissue.
10 inches is the correct answer.
If the Earth's axis were closer to "straight up and down" than
the present 23.5°, then . . .
-- The areas around the north and south poles where the sun
can be up or down for more than 24 hours would be smaller.
-- The "Tropic Zone", between the Tropic of Cancer and the
Tropic of Capricorn, where it's possible for the sun to be
directly overhead, would be narrower.
-- There would be less difference, everywhere, between the
lengths of daylight on the "longest day" and the "shortest day"
of the year.
-- The seasons would be less extreme everywhere. There would
be less difference, everywhere, between the coldest part of the
Winter and the warmest part of the Summer.