Answer:
320 g
Step-by-step explanation:
The half-life of Co-63 (5.3 yr) is the time it takes for half of it to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table as follows:
No. of Fraction Mass
half-lives t/yr Remaining Remaining/g
0 0 1
1 5.3 ½
2 10.6 ¼
3 15.9 ⅛ 40.0
4 21.2 ¹/₁₆
We see that 40.0 g remain after three half-lives.
This is one-eighth of the original mass.
The mass of the original sample was 8 × 40 g = 320 g
Answer:
A liquid changing to a gas is considered a physical change because it involves a change in one or more physical properties, but no change in the fundamental components that make up the substance.
C6H6 is the
most insoluble in water as it is non polar in nature. HCL is highly soluble in
water as it is an electrolyte. Kbr is also highly soluble in water. NaCl
dissolves in water very quickly. CH3CH3OH is also totally soluble in water
because of the Hydrogen bonding formation. It is a well known fact that the
hydrocarbons do not easily mix with water. C6H6 being a strong hydrocarbon does
not mix with water. So among NaCl, KBr, CH3CH3OH, HCl and C6H6, the hydrocarbon
is the least soluble in water.
3.18 grams of product (Cu I) - 2.54 grams of Cu (reactant) = .64 grams of Sulfur, by law of conservation of mass.
