The ozone layer protects humans from harmful UV rays, because it acts as a sort of filter for any toxic or overpowering waves from damaging our skin. This goes for animals, as well.
The chart is about atomic structure: at the top, the left box is "nucleus" and the right is "electron cloud".
On the left, under nucleus, the two boxes are: "protons" on the right and "neutrons" on the left. Under proton is elements which is given and under neutrons, it is "isotopes".
On the right, under electron cloud, the next box is "electrons" and then the lower box is "ions".
Answer:
A) H2O > HCCH > NH3 > CH3CH3
Explanation:
H2O is known as a neural compound which a pH close to 7.0. This however makes it more acidic due to it having the lowest pH when compared to the others in the option.
The other options however have their acidic strength as follows: HCCH > NH3 > CH3CH3. This explains why the pattern of decreasing acidic strength is H2O > HCCH > NH3 > CH3CH3
Answer:
The answer to your question is 0.22
Explanation:
Data
Acetonitrile (CH₃CN) density = 0.786 g/ml
Methanol (CH₃OH) density = 0.791 g/ml
Volume of CH₃OH = 22 ml
Volume of CH₃CN = 98.4 ml
Process
1.- Calculate the mass of Acetonitrile and the mass of Methanol
density = mass/ volume
mass = density x volume
Acetonitrile
mass = 0.786 x 98.4
= 77.34 g
Methanol
mass = 0.791 x 22
= 17.40 g
2.- Calculate the moles of the reactants
Acetonitrile molar mass = (12 x 2) + (14 x 1) + (3 x 1)
= 24 + 14 + 3
= 41 g
Methanol molar mass = (12 x 1) + (4 x 1) + (16 x 1)
= 12 + 4 + 16
= 32 g
Moles of Acetonitrile
41 g ----------------- 1 mol
77.34g ------------ x
x = (77.34 x 1) / 41
x = 1.89 moles
Moles of Methanol
32 g -------------- 1 mol
17.40 g --------- x
x = (17.40 x 1)/32
x = 0.54 moles
3.- Calculate the mole fraction of Methanol
Total number of moles = 1.89 + 0.54
= 2.43
Mole fraction = moles of Methanol / total number of moles
Mole fraction = 0.54/ 2.43
Mole fraction = 0.22
Answer:
nitrogen monoxide: NO
nitrogen dioxide: NO₂
Explanation:
Nitrogen monoxide is composed by 1 atom of O (prefix "mono-") and 1 atom of N. Nitrogen dioxide is composed by 2 atoms of O (prefix "di-") and 1 atom of N. As the oxigen atom in oxides has the valency -2 (it shares 2 electrons), the nitrogen has valency +2 in NO and +4 in NO₂.
