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4 years ago

J. Explain how an atom's valence electron configuration determines its place on the periodic table.

Chemistry

1 answer:

Darya [45]4 years ago

5 0

Answer:

Elements having same valence electrons are placed in <u>same group.</u>

Explanation:

First, let's start with some basic concepts of modern periodic table:

1. Modern Periodic table : It is the arrangement of element in the increasing order of their atomic numbers

The Modern periodic table is divided into Periods and groups .

Periods : These are the horizontal rows. There are seven periods in the periodic table . Period 1 has 2 element. Period two and three has 8 elements , period 4 and 5 have 18 elements and the period 6 and 7 have 32 elements.

Same period have same number of atomic orbital(Shell)

Group : The group is the vertical columns . There are 18 groups in the modern periodic table.Those element which have same group number will also have same number of electron in their outermost shell. The number of electron in the outermost shell determines the valency of the element.

So, elements showing same valency are placed in same group.

All alkali are place in group 1 and have 1 valance electron in the outermost shell

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4. Describe the arrangement of the electrons on each energy level.

never [62]

Answer:

Explanation:

If the energy of an atom is increased, an electron in the atom gets excited. To go back to its ground state, the electron releases energy. The energy of the light released when an electron drops in energy level is the same as the difference in energy between the two levels.

Viewed simply, electrons are arranged in shells around an atom’s nucleus. Electrons closest to the nucleus will have the lowest energy. Electrons further away from the nucleus will have higher energy. An atom’s electron shell can accommodate 2n2 electrons (where n is the shell level).

In a more realistic model, electrons move in atomic orbitals, or subshells. There are four different orbital shapes: s, p, d, and f. Within each shell, the s subshell is at a lower energy than the p. An orbital diagram is used to determine an atom’s electron configuration.

There are guidelines for determining the electron configuration of an atom. An electron will move to the orbital with lowest energy. Each orbital can hold only one electron pair. Electrons will separate as much as possible within a shell.

7 0

3 years ago

A vessel of volume 22.4 dm3 contains 20 mol h2 and 1 mol n2 ad 273.15 k initially. All of the nitrogen reacted with sufficient h

NikAS [45]

Nitrogen combine with hydrogen to produce ammonia $\text{NH}_3$ at a $1:3:2$ ratio:

$\text{N}_2 \; (g) + 3 \; \text{H}_2 \; (g) \leftrightharpoons 2\; \text{NH}_3 \; (g)$

Assuming that the reaction has indeed proceeded to completion- with all nitrogen used up as the question has indicated. $3 \; \text{mol}$ of hydrogen gas would have been consumed while $2 \; \text{mol}$ of ammonia would have been produced. The final mixture would therefore contain

$17 \; \text{mol}$ of $\text{H}_2 \; (g)$ and
$2 \; \text{mol}$ of $\text{NH}_3 \; (g)$

Apply the ideal gas law to find the total pressure inside the container and the respective partial pressure of hydrogen and ammonia:

$\begin{array}{lll} P(\text{container}) &= & n \cdot R \cdot T / V \\ & = & (17 + 2) \; \text{mol} \times 8.314 \; \text{L} \cdot \text{kPa} \cdot \text{mol}^{-1} \cdot \text{K}^{-1} \\ & &\times 273.15 \; \text{K} / (22.4 \; \text{L}) \\ &=& 1.926 \times 10^{3} \; \text{kPa} \end{array}$
$\begin{array}{lll} P(\text{H}_2) &= & n \cdot R \cdot T / V \\ & = & (17) \; \text{mol} \times 8.314 \; \text{L} \cdot \text{kPa} \cdot \text{mol}^{-1} \cdot \text{K}^{-1} \\ & &\times 273.15 \; \text{K} / (22.4 \; \text{L}) \\ &=& 1.723 \times 10^{3} \; \text{kPa} \end{array}$
$\begin{array}{lll} P(\text{NH}_3) &= & n \cdot R \cdot T / V \\ & = & (2) \; \text{mol} \times 8.314 \; \text{L} \cdot \text{kPa} \cdot \text{mol}^{-1} \cdot \text{K}^{-1} \\ & &\times 273.15 \; \text{K} / (22.4 \; \text{L}) \\ &=& 2.037 \times 10^{2} \; \text{kPa} \end{array}$

6 0

3 years ago

A typical thickness for a sheet of paper is 0.004 inches. If you fold a sheet of paper once, the thickness of the folded paper w

Eduardwww [97]

Answer:

Please see the pictures attached below

The first picture has the values and the second has the formulas to construct the spreadsheet.

Explanation:

To construct the spreadsheet you should do the following:

1. First name the four columns as:

Number of folds

Thickness in inches

Thickness in feet

Thickness in miles

2. In the first column "Number of folds" put the numbers from 0 to 50 in order to calculate the thickness of each fold.

3. In the second column "Thickness in inches" put the following formula to show that each fold of a sheet is equal to multiply by 2 the original fold:

Thickness in inches = (thickness in inches(number of folds-1))*2

When the number of folds is 1, the formula will be:

Thickness in inches = 0.000 * 2 = 0.000

When the number of folds is 2, the formula will be:

Thickness in inches = 0.004 * 2 = 0.008

When the number of folds is 3, the formula will be:

Thickness in inches = 0.008 * 2 = 0.016

When the number of folds is 4, the formula will be:

Thickness in inches = 0.016 * 2 = 0.032

And so on until 50.

3. In the third column you only multiply by 0.08333 the value of inches to convert it to feet.

4. And in the fourth column you should multiply the value of inches by 0.0000157828 to convert it to miles.