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3 years ago

Calculate the number of atoms in 0.25 moles of manganese?

Chemistry

1 answer:

White raven [17]3 years ago

3 0

<h3>Answer:</h3>

1.5 × 10²³ atoms Mn

<h3>General Formulas and Concepts:</h3>

<u>Math</u>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

<u>Chemistry</u>

<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>

0.25 mol Mn

<u>Step 2: Identify Conversions</u>

Avogadro's Number

<u>Step 3: Convert</u>

Set up: $\displaystyle 0.25 \ mol \ Mn(\frac{6.022 \cdot 10^{23} \ atoms \ Mn}{1 \ mol \ Mn})$
Multiply: $\displaystyle 1.5055 \cdot 10^{23} \ atoms \ Mn$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 2 sig figs.</em>

1.5055 × 10²³ atoms Mn ≈ 1.5 × 10²³ atoms Mn

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If you follow the octet rule, you know that an element must have 8 outside (or valence) electrons to be energetically favorable.

In CCl4, the carbon molecule forms four bonds; one for each chlorine atom. Each bond contains 2 electrons, so it is satisfied.

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Now, in CCl4, picture the shape of the molecule like a plus sign, with the carbon in the middle and the chlorine at the four ends. It is symmetrical, and therefore is nonpolar.

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3 years ago

1. How is the number of energy levels in an atom related to the period number?

Natalka [10]

Answer:

The highest energy level number (1 through 7) for the electrons in an atom corresponds to the period (or row) in the periodic table to which that atom belongs. Because there are 7 periods in the table, there are 7 energy levels. For example, hydrogen (H) is in the first period, so it has only one energy level.

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3 years ago

Draw the Lewis structures for CH3OH, CH2O and HCOOH. Indicate the hybrid orbital used in the sigma bonds for each of the carbon

sdas [7]

Answer:

See figure 1

Explanation:

For this question, we have to remember that in the lewis structures all atoms must have<u> 8 electrons</u>. And each atom would have a different value of <u>valence electrons</u>:

Carbon => 4

Oxygen=> 6

Hydrogen=> 1

Additionally, for the <u>hybridizations</u> we have to remember that:

$Sp^3$ => 4 single bonds

$Sp^2$ => 1 double bond

$Sp^1$ => 1 double bond

With this in mind, the formaldehyde and formic acid would have $Sp^2$ carbons and the ethanol an $Sp^3$ carbon.

Finally, for the oxidation state. We have to remember that <u>if we have more bonds with oxygen, we will have more oxidation</u>. Therefore, the carbon that has more oxidation is the one in the formic acid (we have several bonds with oxygen).

See figure 1

I hope it helps!