Question

Can y’all help me solve these three questions on my review packet?

Answer 1

Answer:

12.

Infrared has the lower frequency while visible light has a higher frequency.

13.

As = 33

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p³

K = 19

1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹

Sr = 38

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s²

Kr = 36

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶

14. SEE ATTACHED PICTURE

Explanation:

12. The relationship between wavelength and frequency can be seen in the equations:

$F=\dfrac{c}{\lambda}$ and $\lambda=\dfrac{c}{F}$  

Where:

λ = wavelength

F = frequency

c = constant (speed of light)

As you can see that they are indirectly proportional. So as the frequency increases, the wavelength decreases and vis-a-vis.

13. Electronic configuration of an element can be determined using the pattern attached. It determines the electronic structure of an atom.  Remember:  

s subshell holds 2 electrons

p subshell holds 6 electrons

d subshell holds 10 electrons

f subshell holds 14 electrons

You know when to stop when the number of electrons sum up to the atomic number (which is the number of protons) in a stable atom.  

As = 33

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p³ (Stop here because the electrons sum up to 33)

K = 19

1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹

Sr = 38

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s²

Kr = 36

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶

14. Lewis Dot symbol represents how many valence electrons an atom has. You can determine the Lewis Dot Structure also based on the electronic configuration of the element by adding up the number of electrons there are in the highest energy level. The energy level is indicated by the numerical coefficient.

S = 16

1s² 2s² 2p⁶ 3s² 3p⁴

Notice that the highest energy level that appears here is 3, so add up the number of electrons.  

2 + 4 = 6 (This is how many valence electrons Sulfur (S) has.)

So we draw the symbol of Sulfur and put three dots around it.  

C = 6  

1s² 2s² 2p²  

2 + 2 = 4

Sr = 38

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s²

2 valence electrons (Because there are only 2 electrons in the 5th energy level)

*Fe = 26

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶

2 valence electrons (Because there are only 2 electrons in the 4th energy level)

Al = 13  1s² 2s² 2p⁶ 3s² 3p¹

2 + 1 = 3

*Note: Fe or Iron is a transition metal. Technically, 3d in this case is a higher energy level. However, when it comes to Lewis dot structure, d and f shells that are not filled are usually omitted, so it will follow the 4s.  Generally when putting dots around we follow the sequence of the X element shown in the attached file.