One fourth means (one half) of (one half) .
So the 18 months must be two half-lifes.
The half-life of this particular isotope is 9 months.
Answer:
situated on or toward the side sheltered from the wind; downwind. Explanation:
kinda like the water cycle
Answer:
radiant. energy into chemical energy
Answer:
rock that forms when melted rock (magma, lava) cools and hardens
Explanation:
Igneous rock, or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. The magma can be derived from partial melts of existing rocks in either a planet's mantle or crust.
Brainliest plz