Answer: It is the principle that matter cannot be created or destroyed.
Explanation:
True
Density = mass/volume
Suppose that a block has a mass of 20 g and a volume of 20 cm^3.
Density = 20 g/20 cm^3 = 1 g/cm^3
Now, you cut the block in half. The half-block has a mass of 10 g and a volume of 10 cm^3.
The density of the half-block is
Density = 10 g/10 cm^3 = 1 g/cm^3
The density <em>stays the same</em>, even though the size of the sample has changed.
The structure of proteins is ultimately determined by the sequence of nucleic acids.
B. Endorphins are released during exercise
Carbon can form a maximum of 4 covalent bonds because it has 4 valence electrons i.e. 4 outer electrons.
