I think you meant 2.42*10^-6
Remember, the first digit must be between 1 and 10 or - 1 and - 10.
(2.42*10^-6)(1000)
=0.242mm
The answer is 32.43 because when you round the number next to the hunthers place (witch in this problem would be the 1) has to be 5 or hight to raise the number to the left of it and if it is lower you just take the two number and that is your answer.
<h3>
Answer:</h3>
121 mol CH₄
<h3>
General Formulas and Concepts:</h3>
<u>Math</u>
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Chemistry</u>
<u>Organic</u>
- Writing chemical compounds
- Writing organic structures
- Prefixes
- Alkanes, Alkenes, Alkynes
<u>Atomic Structure</u>
- Using Dimensional Analysis
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
<h3>
Explanation:</h3>
<u>Step 1: Define</u>
7.31 × 10²⁵ molecules CH₄
<u>Step 2: Identify Conversions</u>
Avogadro's Number
<u>Step 3: Convert</u>
<u />
<u />
<u />
<u>Step 4: Check</u>
<em>Follow sig fig rules and round. We are given 3 sig figs.</em>
121.388 mol CH₄ ≈ 121 mol CH₄
Atomic mass of boron = 10.81
<h3>What are Isotopes?</h3>
Isotopes are variants of a particular element in which they have the same number of protons but differ in the number of neutrons in the atom.
So, here as we said we have isotopes which weigh 10.01 and 11.01.
Given,
relative abundance of B-10 = 10.1 amu
relative abundance of B- 11 = 11.01 amu
percentage of B-10 = 20%
percentage of B-11 = 80%
Then the relative atomic mass depends upon the relative abundance of various isotopes of that particular element. Suppose an element consists of two isotopes and average atomic mass is equal to
(Relativeabundance(1)×Atomicmass(1)+Relativeabundance(2)×Atomicmass(2)) / (Relativeabundance(1)+Relativeabundance(2))
Atomic mass of boron = (20 × 10.01 + 80 × 11.01) / (80 + 20 )
= 1081/100
= 10.81
To learn more about atomic mass from the given link
brainly.com/question/3187640
#SPJ4
Copper oxide<span> is a base because it will react with acids and neutralise them, but it is</span>not<span> an alkali because it </span>does not dissolve in water. Sodium hydroxide is a base because it will react with acids and neutralise them. It's also an alkali because itdissolves in water<span>.</span>