Answer:
Explanation:
1. Add the atomic mass of all the elements.
39+55.8+12+14= 120.8
2.Divide atomic mass of potassium by total atomic mass

2. Multiply by 100
%32.3
Answer: Plate tectonics was Wegener's theory that Earth's continents rest on sections of Earth's crust that drift together and apart over time; continental drift is a hypothesis describing how plate tectonics might happen.
Explanation: Tectonic plate movement is a long-term environmental change.
If the conjugate base of a molecule has a pKb of 1.4, the molecule should be a Weak Acid.
Notice this question gives us the pKb of the molecule, not the pKa. Because of this, the pH scale basically gets reversed, so lower numbers in pKb correlate with stronger bases, and higher numbers in pKb correlate with stronger acids - the exact opposite of the pH scale.
It's important to make sure you completely understand the terms of conjugate base, conjugate acid, pKb, pKa, and how they all relate. It's easy to mix up the meanings of these definitions.
Here are the two other pieces of information you need to know to correctly answer this question:
- Strong acids have a weak conjugate base.
- Strong bases have a weak conjugate acid.
So if the problem says you have a strong conjugate base, then the molecule must be a weak acid. To illustrate this, think of ammonium, NH4+. Ammonium is a weak acid, but the conjugate base of ammonium is ammonia, NH3, which is a reasonably good base.
Learn more about conjugate base here : brainly.com/question/22514615
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