Answer:
The final temperature of the system is 27.3°C.
Explanation:
Heat lost by aluminum = 3.99 × 0.91 × (100-T)
= 3.631 (100-T)
Heat gained by water = 10 × 4.184 × (T-21)
= 41.84 (T-21)
As,
Heat gained = Heat loss
or, 3.631(100-T) = 41.84(T-21)
or,363.1 - 3.631 T = 41.84 T - 878.64)
or, (41.84+ 3.631) T = 878.64 +363.1
or T= 
or, T = 27.3°C
Hence the final temperature is 27.3°C.
Answer:
B
Explanation:
Pasted below is his 5 theory's and all of them are the building blocks of chemistry today.
1. Matter is made up of atoms that are indivisible and indestructible.
2. All atoms of an element are identical.
3. Atoms of different elements have different weights and different chemical properties.
4. Atoms of different elements combine in simple whole numbers to form compounds.
5. Atoms cannot be created or destroyed. When a compound decomposes, the atoms are recovered unchanged.
Answer: The age of the tool is 15539 years
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant = 100
a - x = amount left after decay process = 
a) for completion of half life:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
b) for 15.5 % of original amount
Thus age of the tool is 15539 years
we are asked in this problem to determine the mass of a liquid in a small container. In order to determine the mass, we use an analytical balance for greater accuracy by first weighing the whole system (liquid+beaker). Then transfer the liquid to another container and completely dry the beaker (wash and dry). measure the weight of the beaker. The mass of the liquid is equal to the mass of the system minus the mass of the beaker.
