i can hardly see it sry...
A. because atoms create crystal structures to form different kind of materials
Answer : The correct option is, 
Explanation :
Amino acid : The acid that contains two functional groups that are carboxylic group,
and ammine group,
.
When the two or more that two amino acids join together with the help of peptide bond, they produces polypeptide chain or protein.
The bond present between the two amino acid is called a peptide bond.
The peptide bond is a chemical bond that is formed between the two molecules when the nitrogen of one amino acid react with the carbon of another amino acid by releasing a water molecule. This is a dehydration synthesis or condensation reaction.
From this we conclude that, only two functional groups carboxylic group,
and ammine group,
are present in all amino acids.
Hence, the correct option is, 
Halogens (atoms with 7 valence electrons) and Hydrogen
or generally, atoms with their shells almost full
Answer:
Physical Property
Explanation:
Density, mass, volume, color, melting and boiling points, etc. are all physical properties. No matter what changes, the chemical makeup stays the same.
Flamability, acidity, toxicity, etc. are chemical properties, because they chemically change the makeup of the object/thing.