Answer:
According to the following position vs. Time graph the bicyclist was : D
D. Not moving for the first two seconds, then begin moving at the constant speed.
Explanation:

Along Y-axis = Distance in meters
Along X-axis = Time taken in second
- For first 2 seconds the The object has not changed its position.There is Zero distance covered.So , Speed = 0
- After 2 second,The Object changed the distance by equal amount in equal interval of time.(Uniform Speed).Hence at each point after 2 second, there is same value speed
Explanation:
For Mg, (1.2 g Mg/24 g Mg) = 0.05 mol Mg.
For Cl, (3.55 g Cl/35.5 g Cl) = 0.1 mol Cl
So the ratio now is
Mg:Cl = 0.05 : 0.1 = 1:2
I got the 1:2 ratio by dividing both by the smallest number, which is 0.05 mol. Therefore, the empirical for formula of the substance is 
Answer:
<em><u>The products of the combustion of hydrocarbons are carbon dioxide and water. Many hydrocarbons are used as fuel because their combustion releases very large amounts of heat energy.</u></em>
Answer:
(A) The intermolecular attraction between HF molecules are stronger than between HCl molecules mainly to due hydrogen bonding.
Explanation:
Since Flourine is highly electronegative and as such, when it bonds with Hydrogen it forms a hydrogen bond. Whereas the HCL molecule is a polar molecule whose inter-molecular forces are dipole dipole interactions. Although a Hydrogen bond is a type of dipole dipole interaction it is stronger than the traditional dipole dipole forces and London dispersion forces. HF also has a shorter bond length which makes the bond and inter-molecular forces stronger as compared to HCL.
What's the question? I don't understand where the problem is.