13% of total energy ( net energy ) is obtained from renewable sources and about 46% of it comes from hydroelectric power plants.
Answer: E. 78%
Explanation:
Diborane (B2H6), a chemical compound made up of approximately 78% Boron and 22% Hydrogen.
Answer:
Explanation:
You are not really helped by what is hold the liquid. Beakers and cylinders come on a lot of sizes. I hate to be crabby about things like that, but you really need to be aware that the question is slightly flawed (not your fault).
The beaker, you'd be like to get 1 sig digit. You have to be awfully careful about claiming more. So the and is 50 mL, but that mL is a guess and the 50 is not totally accurate, but what would you say the second digit is? 48 or 47? You don't really know. Maybe even 49.
The graduated cylinder is a little better. Read the bottom of the meniscus (the bottom of the 1/2 bubble). I think you can get 2 sig digs., so the answer is 36 mL. But everything also depends on what you have been told.
Chemical compounds have chemically bonded molecules so that they exhibit different properties (i.e. chemical) compared to the individual molecules comprising the compound. Mixtures are simply the combinations of different molecules and compounds that are not chemically bonded together, and can therefore be separated by physical means. Mixtures usually retain the properties of its components. The hydrogen and oxygen molecules in a mixture do not form strong bonds between each other. The molecules of both gases are only contained in the same space or volume and the individual molecules retain their chemical properties.
A compound containing hydrogen and oxygen molecules exhibit different chemical (and even physical) properties compared to the individual molecules themselves.
Water for example, is a compound with 2 hydrogen atoms and 1 oxygen atom, chemically-bonded together. Hydrogen gas is highly flammable, water is not. Oxygen gas is an essential reagent for combustion (or burning) reactions, water is not.
Thus, throwing a lighted match to a gaseous mixture of hydrogen

and oxygen

would create fire, or even an explosion (since hydrogen is flammable and oxygen feeds the reaction). Throwing a match to water vapor

would not create fire.