The reserve of a fossil fuel might be increased if mining or extraction techniques improve so that more of fuel can be extracted for a profit
Answer is: Louis Pasteur (1822-1895) disproved spontaneous generation. He boiled liquid with proteins and other nutrients in S-neck flasks and regular flask to kill all microorganism present. In regular flask liquid showed changes when exposed to air and in S-neck flack there was no change (microorganism can not getting in the flask because the S- neck). When he removed S-neck, liquid changed because microorganisms came in liquid.
Pasteur showed it was not the air itself but particles within the air that had microorganisms.
Question 17:
False; cutting hair would change what it looks like but, braiding it keeps it the same substance it is.
Question 18 :
My best guess would either be A or D. I would lean more towards D because if there are different mixtures then it depends on what you are mixing.
Hope it helps in some way. <3
Answer:
Polarity is a property of molecules that represents the separation of electrical charges within the molecule, depending on the number and type of bonds it possesses.
The covalent bond between two atoms can be polar or apolar. This depends on the type of atoms that make it up: if the atoms are equal, the bond will be apolar (since no atom attracts electrons more strongly). But, if the atoms are different, the bond will be polarized towards the most electronegative atom, since it will be the one that attracts the electron pair with more force.
For each of the followings covalent bonds the direction of polarity is the one shown in the picture.
We see that in the C-O bond oxygen is more electronegative than carbon. Therefore, there will be a dipole vector oriented towards of the oxygen. We can represent this polarization of the bond by means of an arrow, which always points to the most electronegative atom.
Explanation:
The polarity of a chemical bond occurs when there is an asymmetric distribution of the electronic cloud of the bond around the two atoms that make up that link. This happens when both atoms have different electronegativity.
- Each bond composed of different atoms generates a dipole vector, which points to the most electronegative atom.
- A molecule will have as many vectors as it has covalent bonds.
- If the vectors do not cancel out, then the molecule will be polar.