Answer:
64
Explanation:
Nitrogen combines directly with oxygen at very high temperatures to form nitrogen(ii) oxide. This is the reaction that occurs during lightning flashes. Atmospheric nitrogen and oxygen combines during the high temperatures obtained in lightning flashes to form nitrogen (ii) oxide.
Equation of the reaction is given below:
N(g) + O(g) ---> 2NO(g)
From the equation of the reaction, 1 mole of nitrogen gas combines with one mole of oxygen gas to produce 2 moles of nitrogen (ii) oxide.
Therefore, 2 moles of oxygen gas will react with 2 moles of nitrogen gas
Mass of oxygen gas that is 2 moles of the gas is obtained from the formula; mass = number of moles * molar mass
Molar mass of oxygen gas = 32.0 g/mol
Mass of 2 moles of oxygen gas = 2 * 32.0 = 56 g
Therefore, the mass of oxygen required in grams is 64
Answer:
Feathers initially evolved in a role associated with sexual selection.
Explanation:
In species where only males had feathers, these feathers can be considered to have evolved into a role associated with sexual selection. This is because in these species, males used their feathers as a sexual attraction for females, in this case, females chose the males that had more attractive feathers to mate and generate new individuals for the species. An example of this can be seen in the peacock, where the tail with lush feathers is only present in males and is intended to sexually attract females.
Answer:
I think it is A. Metaphase
Answer: B. Osmosis Across a Membrane
The movement of water across a gradient is called osmosis.
I believe the answer is A, Cholesterol.
