Answer:
Step-by-step explanation:
Answer:
Amount of Niobium-91 initially
= 300/91 =3.2967mol
2040 years = 3 ×680 = 3 half-lives
therefore, amount left = 0.4121mol
mass of Niobium-91 remaining = 0.4121 ×91 =37.5g
Please give brainliest
The answer is -4 2/3
Explanation : The elevator is at 0, and went below ground level 90 feet, that would be -90, then it went up 20 feet, which would be -90 + 20 = -70
-70 ft / 15sec = - 4 2/3
I am not sure about the ground level and negative difference but that it is what I was taught. Below ground level is negative and above is positive. Therefore the elevator traveled up and it traveled -4 2/3 per second.
It so either 4 2/3 or - 4 2/3 but pretty sure it is - 4 2/3.
:)))
Answer:
To find the surface area of a prism, find the area of a base and double it since the areas of the two bases are always equal. Then find the area of each side face, and add to the area of the bases. A pyramid has one base and triangular sides.
Step-by-step explanation:
