Answer:
A. unexpected change in odor
Explanation: Common physical changes include melting, change of size, volume, color, density, and crystal form. Example the classic baking soda and vinegar reaction provides evidence of a chemical change due to the formation of a gas and a temperature change.
I think Indirect, I’m so sorry if I’m wrong :(
The correct option is this: BF3 IS SYMMETRICAL WHILE NF3 IS UNSYMMETRICAL.
Symmetry is used in chemistry to explain the structure of chemical substances, that is, it is used to explain how the particles in chemical substances are arranged. In chemistry, molecular symmetry is used to explain the behavior of chemical substances. A chemical substance is said to be symmetrical if its polar bonds are evenly distributed; it is described as unsymmetrical if its bonds are unequally distributed. In the compound BF3, the bond dipoles cancel one another out because the polar bonds are evenly distributed whereas in NF3, the bond dipoles were not able to cancel each other out because of unequal distribution of the polar bonds, the compound has a net dipole moment.
The precision of a tool can affect the measurement's accuracy. how specific the measurement can get (if it goes to the tenths place, hundredths, etc) can also affect the accuracy.
This is a statement of the law of Definite Proportions. Basically what it says is that the proportions of mass will always be the same and can't be changed.