A fixed shape. gasses do not have a definite volume (which stems from lack of definite shape) which is why their volume is the same as the container they are being held in.
Generally chemists measure substance in moles because it is very difficult to count the number of molecules<span />
Answer:
1st one is right..it helps filter waste inside the cell.
a core of protons and neutrons surrounds by electrons
Answer : A nucleotide is composed of a phosphate group and a nitrogen-containing base.
Explanation :
Nucleotide : It is a building block of nucleic acids or we can say that it is building block of DNA and RNA.
It is composed of three sub-unit molecules which are a nitrogenous base, a five-carbon sugar and one phosphate group.
Nucleotide forms covalent bonds with other nucleotide for the formation of the nucleic acid strand.
Hence, a nucleotide is composed of a phosphate group and a nitrogen-containing base.