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 5.5 m.
Cube
Volume = length x width x height
Since the length, width and the height are the same in cube, the formula can be:
Volume = length^3
Let x metres be the side length of the cube.
166 = x^3
x = ∛166
x = 5.495864.....
x = 5.5 (nearest tenth)
<span>Which of these numbers is irrational?
a. square root of 3
b. 0.25
c. 1/5
d. square root of 9
answer
</span><span>a. square root of 3
</span><span>--------------------------------
What is (-7)^5 in expanded form?
a. -7 • -7 • -7 • -7 • -7
b. -7 • 5
c. (-7) • 7 • (-7) • 7 • (-7) • -7
d. 5 • 5 • 5 • 5 • 5 • 5 • 5
answer
</span><span>a. -7 • -7 • -7 • -7 • -7 </span>
1 hundredth+3 tenths= 3 hundredths
