Membranes are barriers and “gatekeepers”, they only let certain molecules pass through them.
they also transport nutrients to the cell
I’m pretty sure it’s B since ones charge the neutral while ones is positive, it’s an obvious difference as well/
An imaginary line joining a planet and the sun sweeps out an equal area of space in equal amounts of time. Thus, the speed of the planet increases as it nears the sun and decreases as it recedes from the sun.
1) Answer is: molar mas of ammonia is 17.031 g/mol.
M(NH₃) = Ar(N) + 3 · Ar(H) · g/mol.
M(NH₃) = 14.007 + 3 · 1.008 · g/mol.
M(NH₃) = 17.031 g/mol.
2) Answer is: molar mas of lead(II) chloride is 278.106 g/mol.
M(PbCl₂) = Ar(Pb) + 2 · Ar(Cl) · g/mol.
M(PbCl₂) = 207.2 + 2 · 35.453 · g/mol.
M(PbCl₂) = 278.106 g/mol.
3) Answer is: molar mas of acetic acid is 60.052 g/mol.
M(CH₃COOH) = 2 · Ar(C) + 2 · Ar(O) + 4 · Ar(H) · g/mol.
M(CH₃COOH) = 2 · 12.0107 + 2 · 15.9994 + 4 · 1.008 · g/mol.
M(CH₃COOH) = 60.052 g/mol.
