Answer:
Part 1: W = 116 Y = 163
Part 2: Since 232 is the mailing point of 2 kg then you would divide 232 by 2 to get the melting point for 1 kg, the same with Y.
B. When scientific understanding changes.
Answer:
(a) I⁻ (charge 1-)
(b) Sr²⁺ (charge 2+)
(c) K⁺ (charge 1+)
(d) N³⁻ (charge 3-)
(e) S²⁻ (charge 2-)
(f) In³⁺ (charge 3+)
Explanation:
To predict the charge on a monoatomic ion we need to consider the octet rule: atoms will gain, lose or share electrons to complete their valence shell with 8 electrons.
(a) |
I has 7 valence electrons so it gains 1 electron to form I⁻ (charge 1-).
(b) Sr
Sr has 2 valence electrons so it loses 2 electrons to form Sr²⁺ (charge 2+).
(c) K
K has 1 valence electron so it loses 1 electron to form K⁺ (charge 1+).
(d) N
N has 5 valence electrons so it gains 3 electrons to form N³⁻ (charge 3-).
(e) S
S has 6 valence electrons so it gains 2 electrons to form S²⁻ (charge 2-).
(f) In
In has 3 valence electrons so it loses 3 electrons to form In³⁺ (charge 3+).
<u>Answer:</u> The correct answer is Option 3.
<u>Explanation:</u>
All the radioisotope decay processes follow first order kinetics.
Rate law expression for first order kinetics is given by the equation:
where,
k = rate constant = ?
t = time taken for decay process = 8.32 seconds
a = initial amount of the reactant = 80 mg
a - x = amount left after decay process = 20 mg
Putting values in above equation, we get:
The equation used to calculate half life for first order kinetics:
where,
= half life of the reaction = ?
k = 
Putting values in above equation, we get:
Hence, the correct answer is Option 3.
