Hey there!
A half-life means after a certain amount of time, half of that substance will be gone/changed after that time.
If 50%, or half, of the element remains after 4000 years, that means the half life must be 4000 years.
Hope this helps!
Answer:
The correct answers are:
"Only about 3 percent of Earth's water is fresh water."
"About 75% percent of the fresh water on Earth is frozen in ice sheets."
"The largest source of usable fresh water is groundwater."
Explanation:
3 percent of Earth's water is most certainly fresh water. Confirmed with a few fact checks.
The largest source of usable fresh water on Earth is groundwater. It's more difficult to access but it's there and much more usable than water say frozen in ice on the sea.
The most correct option left would be 75% of Earth's freshwater being in ice sheets even though it's about 70%.
Molecular Formula of Propanoic Acid is....
C₃H₆O₂Where;
Atomic Mass of C = 12
Atomic Mass of H = 1
Atomic Mass of O = 6
Substituting Atomic Masses in molecular formula,
(12)₃ + (1)₆ + (16)₂
36 + 6 + 32
74 g/mol
Result:
Molecular Mass of Propanoic Acid is 74 g/mol. Structure of Methyl Ethanoate and Propanoic Acid are as follow,
Answer:
7.7439×10⁻³¹ m
Explanation:
The expression for Heisenberg uncertainty principle is:

Where m is the mass of the microscopic particle
h is the Planks constant
Δx is the uncertainty in the position
Δv is the uncertainty in the velocity
Given:
mass = 0.68 g = 0.68×10⁻³ kg
Δv = 0.1 m/s
Δx= ?
Applying the above formula as:

<u>Δx = 7.7439×10⁻³¹ m</u>