Answer: 3. The half- life of the isotope must be long enough to capture the age of the rock. and
4. their should be more than one unstable isotope.
In radioactive dating proces, the parent isotope is in unstable state which undergoes decay process to give stable daughter isotopes. Half-life is the amount of time it takes for half of the parent isotopes to decay. The rock dating requires a long lived parent isotope so that it can capture the exact rock age.
One rock when get decayed in the daughter isotope other will be available identify the age.
Answer:
plant: This Elodea leaf cell exemplifies a typical plant cell. It has a nucleus, and a stiff cell wall which gives the cell its box-like shape. The numerous green chloroplasts allow the cell to make its own food (by photosynthesis).
The central vacuole takes up most of the volume of the cell. It is transparent, but you can see where it's pressing the chloroplasts up against the cell wall, especially at the ends of the cell.
Like animal cells, the cytoplasm of this plant cell is bordered by a cell membrane. The membrane is so thin and transparent that you can't see it, but it is pressed against the inside of the cell wall.
animal :This human cheek cell is a good example of a typical animal cell. It has a prominent nucleus and a flexible cell membrane which gives the cell its irregular, soft-looking shape.
Like most eukaryotic cells, this cell is very large compared to prokaryotic cells. For scale, notice the pair of dark blue bacteria cells sticking to the right edge of the cheek cell. The bacteria are only a fraction of the size of the nucleus, but their tiny size is typical for bacteria.
The conditions listed above are common side effects of DEPRESSANTS. Depressants are drugs which slowed down the central nervous system an the brain. They are usually used to treat anxiety and sleep disorders. Other side effects of depressants include: slurred speech, impaired memory and judgement, lowered inhibition, etc.
The indentation on the medial surface of each lung through which
pulmonary and systemic blood vessels, bronchi, lymphatic vessels, and
nerves enter and
leave is called the hilum
