Answer:
Approximately 1.9 kilograms of this rock.
Explanation:
Relative atomic mass data from a modern periodic table:
To answer this question, start by finding the mass of Pb in each kilogram of this rock.
89% of the rock is 
. There will be 890 grams of in one kilogram of this rock.
Formula mass of :
.
How many moles of formula units in that 890 grams of ?
.
There's one mole of 
in each mole of . There are thus 
of in one kilogram of this rock.
What will be the mass of that of ?
.
In other words, the in 1 kilogram of this rock contains 
of lead .
How many kilograms of the rock will contain enough to provide 1.5 kilogram of ?
.
Answer:
There are 3600 pages to 2 significant figures
Explanation:
Working only with the information given, we have that there are 23 books each with about 31 chapters.
This means that if 1 book has 31 chapter, the 23 science books will have
31 X 23 chapters =713 chapters in total.
If each chapter contains 5 pages, for the 713 chapters we will have a total of 713 X 5 pages = 3565 pages.
Rounding off the answer to 2 significant figures , we are looking to have only two non-zero figures in our answer. To do this, we count two numbers from the left. This will be numbers 3 and 5.
Next, we check the net number after 5 to see if it is greater than 5 if it is, we will have to add the number (1 ) to the 5. This shows that we are approximating upwards, to account for the fact that that number has passed the middle point.
After this, we change the remaining two numbers (6 and 5) to zeroes.
This will give us 3600 pages.
Answer:-
2.0 L
Explanation:-
Initial Volume = V 1 = 3.0 L
Initial Pressure P 1 = 4.0 atm
New pressure P 2 = 6.0 atm
Using boyle's law
P1 V1 = P2 V2
New Volume V2 = P1 V1 / P2
= 4.0 atm x 3.0 L / 6.0 atm
= 2 .0 L
Take 23mols and multiply it by the atomic mass of Li:
23mol * 6.94g/mol = 159.62g
