O2.
Because it is only made up of one type of element it is an element. Howevern there is more than one oxygen atom because oxygen cannot exist as a single atom, therefore making it a molecule as well.
Answer: The last one
Explanation: because Im in the 8th grade and I did this in the 6th
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Answer: The energy of a mole of photon associated with this frequency is 
Explanation:
The energy and frequency are related by :
E = energy of photon
N = number of moles = 1
h = planks constant = 
= frequency = 
The energy of a mole of photon associated with this frequency is
C.)Cool air near the surface forms high-pressure areas; warm air forms low-pressure areas.
Explanation:
The relationship between air temperature and high and low pressure air is such that cool air near the surface forms high-pressure areas and warm air forms low pressure areas.
- Cool air is closer to the surface because it has low kinetic energy to move. It is denser.
- Warm air rises sharply away from the ground surface.
- They form low pressure areas and their molecules are wide apart due to their high kinetic energy. The air is less dense.
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Kinetic energy brainly.com/question/9924094
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