Answer:
He was the first scientist to observe and describe bacteria and protozoa by looking at a drop of water from a pound under a microscope. He also was the one to build the first compound microscope.
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Answer:
pressure of gas are constant describe the relationship between moles and temprature
Answer:
Distance cover = 8 km
Explanation:
Given:
Speed of runner = 4 km/h
Time taken = 2 hour
Find:
Distance cover
Computation:
Distance = Speed x Time
Distance cover = Speed of runner x Time taken
Distance cover = 4 x 2
Distance cover = 8 km
Answer:
0.50 mol
Explanation:
The half-life is <em>the time required for the amount of a radioactive isotope to decay to half that amount</em>.
Initially, there are 8.0 moles.
- After 1 half-life, there remain 1/2 × 8.0 mol = 4.0 mol.
- After 2 half-lives, there remain 1/2 × 4.0 mol = 2.0 mol.
- After 3 half-lives, there remain 1/2 × 2.0 mol = 1.0 mol.
- After 4 half-lives, there remain 1/2 × 1.0 mol = 0.50 mol.
Answer:
The molar mass of dry air = 28.94
Density = 1.29
Explanation:
Mm of N2= 28, Mm of O2= 32, Mm Ar= 39.9
78% of N2 by mole give = 0.78×28= 21.84
21% of O2 by mole give = 0.21× 32= 6.72
1% of At by mole give = 0.01× 39= 0.39
Hence overall molecular weight of air = 21.84+6.72+0.39= 28.94
Density = m/ v,
1- mole of air occupy 22.4dm^3 volume
Density= 28.94/22.4= 1.29
