It should be a chemical change
<u>Answer:</u> The force that must be applied is 15 N.
<u>Explanation:</u>
Force exerted on the object is defined as the product of mass of the object and the acceleration of the object.
Mathematically,

where,
F = force exerted = ?
m = mass of the object = 3 kg
a = acceleration of the object = 
Putting values in above equation, we get:

Hence, the force that must be applied is 15 N.
Answer:
Nitrifying Bacteria are a group of aerobic bacteria important in the nitrogen cycle as converters of soil ammonia to nitrates, compounds usable by plants. An example is nitrosomonas or nitrobacter and species in that family.
The schematic diagram is attached below, which summarises the oxidation of ammonia or free nitrogen in the soil to nitrates for the cowpea plant's utilisation.
Answer: B (to provide a statement that can be tested with an experiment
Answer:
A
Explanation:
What the equation is tell you is that for every 3 mols of NO2 you get 2 mol of HNO3
3 mol NO2 / 2 mol HNO2 ===> 300.00 mol NO2 / x Cross multiply
3x = 2 * 300
3x = 600 Divide by 3
3x/3 = 600/3 Do the division
x = 200.00