The energy<span> per </span>photon<span> is proportional to the </span>frequency<span> of the radiation when considered as waves, ie inversely proportional to the </span>wavelength. Double the wavelength<span>, halve the </span>photon energy<span>. This means that long </span>wavelength<span> radiation (radio waves) has low </span>photon energy<span> and so does not penetrate matter.</span>
B.
The cynobacteria were already there without the oxygen, so that rules out A, and a lot of prokaryotes were anaerobic, so that rules out C. Finally, Photosynthesis does not require oxygen. Instead, Oxygen is a waste product of it. Therefore, it cannot be D. So, we are only left with B
Hoped this helped :D
Answer: Which Group 1A elements are less dense than pure water at 4 degrees C? Li Na K. How does density vary with temperature? Temperature up, density down.
Explanation:
Answer:
NaCl will only conduct electricity in solutions
Explanation:
For electrical conduction, free mobile electrons as seen in most metals must be present or ions which are charged particles must be available for solutions and molten substances.
- Sodium chloride is an ionic compound without free mobile electrons or ions despite being ionic.
- It will maintain a subtle and unique charge stability when in solid form.
- In solid, the ions are not free to move and remain locked up in the solid mass.
- When introduced into a solution, the ions becomes free to move and this will aid electrical conduction.
Explanation:
The halogen family and noble gases are similar in just one particular way, they are groups of non-metals. All members of these two groups are categorized as non-metals.
Here are some of the differences between them;
- Halogens have 7 electrons in their outermost shell whereas noble gases have 8 electrons in theirs.
- Halogens are highly reactive elements, noble gases are non-reactive.
- Halogens are made up of electronegative elements where as noble gases are neither electropositive nor electronegative.