4Al + 3O2 —> 2AL2O3
Answer is D
Dissolution means to make the compound apart, So when we have ionic compounds like NaI which has metal and non-metal ions, It separates into parts of positive ions and negative ions. After we separate this compound apart we will put the charge of each on above its symbol and then start to balance the equation of the dissolution.
So the dissolution equation of NaI is:
NaI(s) → Na^+(s) + I^-(Aqu)
Answer:

Explanation:
The relation between frequency and wavelength is shown below as:
c is the speed of light having value
Given, Wavelength = 188 μm
Also, 1 μm =
nm
So,
Wavelength =
m
Thus, Frequency is:

Answer:
1.085 x 10²⁴
Explanation:
The answer is not in your choices, but it maybe due to a typo but to get the answer to this, you just need to convert the grams to moles, then moles to atoms.
First we get the mass of the molecule for every mole. Get the atomic mass of each element and multiply it by the number of atoms present then get their total.
N₂O₃
Element number of atoms Atomic mass TOTAL
N 2 x 14.007 28.014
O 3 x 15.999 <u>47.997</u>
76.011 g/mole
So now we know for every 1 mole of N₂O₃ there are 76.011 g of N₂O₃.
Next we need to see how many moles of N₂O₃ are there in 137.0g of N₂O₃.

Now we know that we have 1.802moles of N₂O₃.
We use Avogadro's constant to find out how many atoms there are. Avogadro's constant states that for every mole of any substance, there are 6.022140857 × 10²³ atoms.

a) chemical energy
b) by electricity
c)
(i) Light
(ii) thermal transfer
<em>By </em><em>Benjemin</em>