Answer:
3 years
Explanation:
Given data:
Initial amount of sample = 160 Kg
Amount left after 12 years = 10 Kg
Half life = ?
Solution:
at time zero = 160 Kg
1st half life = 160/2 = 80 kg
2nd half life = 80/2 = 40 kg
3rd half life = 40 / 2 = 20 kg
4th half life = 20 / 2 = 10 kg
Half life:
HL = elapsed time / half life
12 years / 4 = 3 years
Answer:
Element with 6s subshell
Explanation:
Reactivity of an element depends on the electronic configuration and position of element in the periodic table as reactivity increases as we go down the periodic table.
This is so because number of shell increases as move down the periodic table and the last electron is further away from the nucleus.
Element with 6s subshell is the largest among 3s and 4s subshell and has more number of shells so it will react more than 3s and 4s subshell.
Hence, the correct answer is "Element with 6s subshell".
Answer:
The nuclear charge increases from boron to carbon, but there is no additional shielding( that is no additional shells).
Explanation:
First of all, we must know the electron configuration of carbon and boron.
Boron- 1s2 2s2 2p1
Carbon- 1s2 2s2 2p2
Moving from boron to carbon, the effective nuclear charge increases without a corresponding increase in the number of shells. Remember that shielding increases with increase in the number of intervening shells between the outermost electron and the nucleus. Since there isn't an increase in shells, boron experience a lower screening effect.
From
Zeff= Z- S
The Z for carbon is 6 while for boron is 5 even though both have the same number of screening electron S(4 screening electrons). Hence it is expected the Zeff(effective nuclear charge) for boron will be less than that of carbon.
Answer:
A.
Explanation:
There are no vehicle emissions other than water vapor. This means no pertroleum products and no fossil fuels. :)
-Sienna Sushi
Answer:
148 g
Explanation:
Step 1: Write the balanced equation for the decomposition of sodium azide
2 NaN₃ ⇒ 2 Na + 3 N₂
Step 2: Calculate the moles corresponding to 95.8 g of N₂
The molar mass of N₂ is 28.01 g/mol.
95.8 g × 1 mol/28.01 g = 3.42 mol
Step 3: Calculate the moles of NaN₃ needed to form 3.42 moles of N₂
The molar ratio of NaN₃ to N₂ is 2:3. The moles of NaN₃ needed are 2/3 × 3.42 mol = 2.28 mol.
Step 4: Calculate the mass corresponding to 2.28 moles of NaN₃
The molar mass of NaN₃ is 65.01 g/mol.
2.28 mol × 65.01 g/mol = 148 g
