Answer:
the answer is actually c
Explanation:
Cold air is more denser than hot air because ,when cold air of some density, say 'd' is heated, the molecules/atoms move apart from each other and so the volume expands. i hope that helped you
Its hard to believe it but its D.<span />
The hydrogen ion concentration of a solution is indicated by its <u>pH </u>value.
Explanation:
- A measure of acidity or alkalinity of water soluble substances (pH stands for 'potential of Hydrogen'). A pH value is a number from 1 to 14, with 7 as the middle point.
- Under normal circumstances this means that the concentration of hydrogen ions in acidic solution can be taken to be equal to the concentration of the acid.
- The pH is then equal to minus the logarithm of the concentration value.
- Values below 7 indicate acidity which increases as the number decreases, 1 being the most acidic.
- The pH of a solution is a measure of hydrogen ion concentration, which in turn is a measure of its acidity.
- Pure water dissociates slightly into equal concentrations of hydrogen and hydroxyl (OH−) ions. For a neutral solution, [H+] is 10−7, or pH = 7.
Answer:
I) Sexual reproduction
II) Mutation
Explanation:
Variations refer to the difference observed within organisms of the same species. Variation are introduced into a population by:
- new genetic combinations that occur during sexual reproduction (i.e during meiosis)
- mutations, spontaneous changes that occur in genes and chromosomes.
Chemical (mutagens)
usually either mimic the structure of nucleotides and are inserted in DNA or either cause
chemical changes (such as alkylation) in nucleotides hence causing mismatching during replication.
Radiation, on the other hand, (due to its high energy) causes double-strand breaks in DNA causing an
increased likelihood of mutations during the repair of the DNA by cell
mechanisms.
