Answer:
12.50g
Explanation:
T½ = 2.5years
No = 100g
N = ?
Time (T) = 7.5 years
To solve this question, we'll have to find the disintegration constant λ first
T½ = In2 / λ
T½ = 0.693 / λ
λ = 0.693 / 2.5
λ = 0.2772
In(N/No) = -λt
N = No* e^-λt
N = 100 * e^-(0.2772*7.5)
N = 100*e^-2.079
N = 100 * 0.125
N = 12.50g
The sample remaining after 7.5 years is 12.50g
Answer:
9.29 mol
Explanation:
Given data:
Number of moles = ?
Mass = 148.6 g
Solution:
Number of moles = mass/ molar mass
Molar mass of CH₄ = 16 g/mol
Now we will put the values in formula.
Number of moles = 148.6 g/ 16 g/mol
Number of moles = 9.29 mol
Thus 148.6 g have 9.29 moles.
Answer:
125.5 ×10^-3 m^3= 0.1255 m^3
Explanation:
Volume=5.6mol×22.414dm^3
=125.5dm^3
Answer:
v = 23.96 cm³
Explanation:
Given data:
Mass = 15.0 g
Density = 0.626 g/cm³
Volume = ?
Solution:
Formula:
D=m/v
D= density
m=mass
V=volume
Now we will put the values in formula:
d = m/v
v = m/d
v = 15 g / 0.626 g/cm³
v = 23.96 cm³
Answer:
Deer, Eagle, Raccoon, frog, turtle, fish, dragonfly.
Explanation:
They interact from the life cycle they eat each other...
