Im pretty sure its h2o so like the 2nd one
Answer
Atomic number or proton number tells us the number of protons found in the nucleus of every atom of that element
Explanation:
Answer:
26.95 %
Explanation:
Air contains the highest percentage of oxygen and nitrogen gases. Magnesium then combines with both of the gases:


Firstly, find the total number of moles of magnesium metal:

Let's say that x mol react in the first reaction and y mol react in the second reaction. This means:

According to stoichiometry, we form:

Multiplying moles by the molar mass of each substance will yield mass. This means we form a total of:

The total mass is given, so we have our second equation to solve:

We have two unknowns and two equations, we may then solve:


Express y from the first equation:

Substitute into the second equation:





Moles of nitride formed:

Convert this to mass:

Find the percentage:

D. details about what happening
Answer:
200 watts
Explanation:
First we have to find total work:
W =F(d)
W = 400J
Then plug that answer into the Power formula.
P = W/(t_f-t-i)
P = 400/2s
P = 200 W