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:
A, B, D & E
Explanation:
Watershed conservation aims to protect wildlife in the watershed, restore vegetation, keep the watershed environment healthy, and in very dire cases may even have to relocate the watershed to a less polluted area
Answer:
The lunar phases gradually change over the period of a synodic month (about 29.53 days), as the orbital positions of the Moon around Earth and of Earth around the Sun shift. The Moon's rotation is tidally locked by Earth's gravity; therefore, most of the same lunar side always faces Earth.
Explanation:
Electric Current. Here are some more words to meet the requirements.
Answer: in order for a scientific investigation to be valid A hypothesis must be tested throughout a Scientific investigation that can gather evidence and support it.
Explanation: in any scientific investigation you have to have a testable hypothesis, without your hypothesis it’s not really a scientific investigation.
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