Answer:
Actinides
Explanation:
They are defined as "any of the series of fifteen metallic elements from actinium (atomic number 89) to lawrencium (atomic number 103) in the periodic table. They are all radioactive, the heavier members being extremely unstable and not of natural occurrence"
Answer:
The correct answer is - A. Ethanol reduces air pollution.
Explanation:
Ethanol is believed to be better fuel for the environment than other petroleum fuels. Ethanol emits lower carbon dioxide as it is clean smokeless fuel, and produces less or the same oxides of nitrogen and hydrocarbons.
It is produced by the process of fermentation of molasses by yeast. Mixing it with the other fuels is found to be CO2 reduces by 30% of emissions to the atmosphere.
Hydrogen bonds
Guanine-cytosine and adenine-thymine <em>hydrogen bonds</em> hold the strands of a DNA helix together.