The answer is 8 :)
All nobel gases have 8 outer electrons.
Answer:
1.08 x 10²⁵molecules
Explanation:
From the mole concept we know that ;
1 mole of any substance contains 6.02 x 10²³ molecules
This number is the Avogadro's number.
So;
18 mole of CH will contain:
Number of molecules of CH = 18 x 6.02 x 10²³ = 1.08 x 10²⁵molecules
The number of molecules is therefore 1.08 x 10²⁵molecules
Answer:
6.31g/mol
Explanation:
Using the ideal gas equation;
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
n = number of moles (mol)
R = gas law constant (0.0821 Latm/molK)
T = temperature (K)
Mole (n) = mass (m)/molar mass (Mm)
* Mm = m/n
Also, density (p) = mass (m) ÷ volume (V)
PV = nRT
Since n = M/Mm
PV = M/Mm. RT
PV × Mm = m × RT
Divide both sides by V
P × Mm = m/V × RT
Since p = m/V
P × Mm = p × RT
Mm = p × RT/P
Mm = 0.249 × 0.0821 × 293/0.95
Mm = 5.989 ÷ 0.95
Mm = 6.31g/mol
The mass of plutonium that will remain after 1000 years if the initial amount is 5 g when the half life of plutonium-239 (239pu, pu-239) is 24,100 years is 2.5 g
The equation is Mr=Mi(1/2)^n
where n is the number of half-lives
Mr is the mass remaining after n half lives
Mi is the initial mass of the sample
To find n, the number of half-lives, divide the total time 1000 by the time of the half-life(24,100)
n=1000/24100=0.0414
So Mr=5x(1/2)^1=2.5 g
The mass remaining is 2.5 g
- The half life is the time in which the concentration of a substance decreases to half of the initial value.
Learn more about half life at:
brainly.com/question/24710827
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Answer:
The dam disrupts the river wildlife and ecosystem.
Explanation:
Though it is believed that using the dam as a power generation or hydroelectric power supply generates no greenhouse gases, it, however, has many disadvantages which make it deemed not suitable or sustainable for use in the contemporary time.
Majorly, the top reason why more hydroelectric dams are not built is that "the dam disrupts the river wildlife and ecosystem."
Also, it affects the water quality and other use of water for humans such as recreational use.
There is also a possible chance of dams producing methane; a greenhouse gas through the organic materials in the water that is rotting.
