Answer:
it's the science of chemicals and liquids!
Water - water is not ever-lasting. Once we consume all the water, there wont be water, and that means there wont be life. Also, if we sum up the wasted water plus the contaminated water, we get a scary amount of water that isn´t being used properly or at all.
Land - land is also a basic need in our lives. We all now that there are alternative solutions to planting on land such as hydroponics, but they don´t work the same. In order to have plants (food), we need to have good and well-took-care-of land.
Air - we need air to breathe, preferably quality air. If we pollute the air we have, we´re damaging a very important resource, plus, if we cut too many trees like we do now, we´re only making things worse.
Hope it helped,
BiologiaMagister
Magnesium plays a vital role in the function and structure of the body.
The adult human body consist of 25 grams of magnesium i.e. 0.25 % of the human body composition approximately.
Therefore, for a 60 kg adult, then the amount of magnesium in their body would be
= 0.15 kg
Convert kg to g:
1 kg = 1000 g
So, 0.15 kg = 
= 150 grams
Thus, amount of magnesium in 60 kg adult is equal to 150 grams
Answer:
Six C atoms (C₆); five H atoms (H₅); one N atom (N); no O atoms
Explanation:
The rule of 13 states that the formula of a compound is a multiple n of 13 (the molar mass of CH) plus a remainder r.
MF = CₙHₙ₊ᵣ
Y has a molecular mass of 91 u
91/13 =7r0
The formula can't be C₇H₇ because a hydrocarbon must have an even number of H atoms,
The odd mass and the odd number of H atoms make it reasonable to add an N atom and subtract CH₂ (CH₂ = 14):
C₇H₇ + N - CH₂ = C₆H₅N
Check:
6C = 6 × 12.000 = 72.000 u
5H = 5 × 1.008 = 5.040
1N = 1 × 14.003 = <u>14.003 </u>
TOTAL = 91.043 u
This is excellent agreement with the observed mass of 91.0425 u.
There are six C atoms (C₆)
There are five H atoms (H₅)
There is one N atom (N)
There are no O atoms.
