Answer:
This means that the isotope of silicon with a mass number of 28 is by far the most common of these three isotopes.
Explanation:
The abundance of Si-28 is 92.23%. Si-29 is 4.68% and Si-30 is 3.09%.
Because most Si atoms have a mass of 28 amu, the average mass of all silicon atoms is very close to 28.
Here is a video which summarizes how to calculate average atomic mass from data about mass and relative abundance.
D. More collisions occur and the time required for the reaction decreases
This happens because according to collision theory, when energy (in this case, thermal energy) is applied to particles, they move/vibrate more quickly.
The answer is 1.5*10^-12 square meters. For a detailed calculation, please refer to the attachment.
Answer:
114 kPa
Explanation:
By Bernoulli's equation when a fluid flows steadily through a pipe:
P + ρ*g*y + v² = constant in the pipe, where P is the pressure, ρ is the density of the fluid, g is the gravity acceleration (9.8 m/s²), y is the high, and v the velocity.
By the continuity equation, the liquid flow must be constant in the pipe, and then:
A1*v1 = A2*v2
Where A is the area, v is the velocity, 1 is the point 1, and 2 the point 2 in the pipe. The are is the circle area: π*(d/2)². So:
π*(0.105/2)²*9.91 = π*(0.167/2)²*v2
0.007v2 = 0.027
v2 = 3.9 m/s
Then:
P1 + ρ*g*y1 + v1² = P2 + ρ*g*y2 + v2²
ρ*g*y1 - ρ*g*y2 + v1² - v2² = P2 - P1
ρ*g*Δy + v1² - v2² = ΔP
ΔP = 1290*9.8*9.01 + 9.91² - 3.9²
ΔP = 113,987.42 Pa
ΔP = 114 kPa
