0.400 g
20.5 g
103 g
Answer : The correct option is, 0.200 g
Solution :
As we know that the radioactive decays follow first order kinetics.
First we have to calculate the rate constant of a samarium-146.
Formula used :
Putting value of in this formula, we get the rate constant.
Now we have to calculate the original amount of samarium-146.
The expression for rate law for first order kinetics is given by :
where,
k = rate constant =
t = time taken for decay process =
a = initial amount of the samarium-146 = 205 g
a - x = amount left after decay process = ?
Putting values in above equation, we get the value of initial amount of samarium-146.
Therefore, the amount left of the samarium-146 is, 0.200 g
Ans: 0.200 g
Given:
Half life of Sm-146 = t1/2 = 103.5 million years
Time period, t = 1.035 billion years = 1035 million years
Original mass of sample, [A]₀ = 205 g
To determine:
Amount of sample after t = 1035 million years
Explanation:
The rate of radio active decay is given as:
Given the two formulas representing the same compound:
Which statement describes these formulas?
(1) Formulas A and B are both empirical.
(2) Formulas A nd B are both molecular.
(3) Formula A is empirical and Formula B is molecular.
(4) Formula A is molecular and Formula B is empirical.
Correct option is (3).
Empirical formula:-Simplest whole number ratio of various atoms present in a compound.
Molecular formula:-The formula that gives the total number of atoms of each element in each molecule of a substance.
So, (formula B) is the molecular formula, and (Formula A)is the empirical formula.
Hence, the correct option is (3).
To know more about:-
b. H₂O
c. NH₃
d. NaCl
e. CO₂
Can anyone explain this one?
Carbon dioxide (CO₂) is a molecule with polar bonds but is considered nonpolar due to its linear shape.
In order to determine whether a molecule is polar or nonpolar, we must consider both the polarity of the individual bonds and the molecular geometry. A molecule with polar bonds can be nonpolar if the bond polarities cancel each other out due to the overall molecular shape.
Out of the given options, the molecule that has polar bonds but is nonpolar is CO₂. Carbon dioxide has two polar bonds between carbon and oxygen, but the molecule has a linear shape, which results in the bond polarities canceling each other out, making the molecule nonpolar.
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(2) 42 g (4) 104 g
Answer: It's 104 g
Explanation: yes