This law states that, despite chemical reactions or physical transformations, mass is conserved — that is, it cannot be created or destroyed — within an isolated system. In other words, in a chemical reaction, the mass of the products will always be equal to the mass of the reactants.
I looked this up but hope it helps!
Answer:
(b)90mg/lb
Explanation:
The child can consume a maximum of 23 tablets with 80mg of acetaminophen, the total acetaminophen ingest is:
This value is for 8 hours, 8 hours is 1/3 of one day. This means that the dose that can be consumed in 24 hours is 3 times 1840mg.
To obtain the maximum allowable dose in mg per pound of body weight, divide this last value by the weight of the child in pounds.
Conversion of units: 
When the volume is 450 cm3 so the boat will displace 450 g.
so we have 450 g - 14.5g = 435.5 left
so to get how many pennies can be added to the boat before it sinks can be determined by:
divided the mass for the one penny:
no.of Penny = 435.5 / 2.5g
= 174.2
∴ the boat will float with 174 pennies and will start to sink with 175
in these options not any Element are liquid at 1000k i think you type wrong in first option It is Hg not Ag and Hg is liquid at 1000 k
