4 clovis chemistry 113 ch 4

The Fifth Series is made of all the elements that have all of their electrons completely contained in the first 5 energy levels. Begins with ends with (54)

Rubidium (37) Xenon (54)

The Third Series is made of all the elements that have all of their electrons completely contained in the first 3 energy levels. Begins with , ends with

Sodium (11) Argon (18)

The s orbital has only one orientation. What does that mean? The p orbital, which has sort of an hourglass shape, has three orientations (px: p for the shape and x because it s straddling the X axis, py: p for the shape and y because it s straddling the Y axis, pz: p for the shape and z because it s straddling the Z axis)

That means that there is only one way to put that sphere so that the point at which the X,Y, and Z axes intersect is the exact center of the sphere. The p orbital, which has sort of an hourglass shape, has threeorientations(px: p for the shape and x because it s straddling the X axis, py: p for the shape and y because it s straddling the Y axis, pz: p for the shape and z because it s straddling the Z axis)

So the 4th would have s, p, d, f and the 5th would have?

The 5th would have s, p, d, f, g

To calculate the maximum number of electrons that can fit in a particular orbital we have to take a look at:

The Pauli Exclusion Rule! In 1925, Austrian physicist Wolfgang Pauli came up with his exclusion principle that is very handy in determining how many electrons each orbital can hold.

What is the mass number?

The atomic weight rounded up to the nearest whole number (Protons + Neutrons)

1s1

The big 1 stands for the 1stenergy level, the s indicates the s orbital, and the superscript 1 tells us how many electrons we are dealing with.

Boron has 5 electrons - where do they go?

The first 2 fill up the first energy level, the other 4 (2 + 2) go into the second energy level.

What does the atomic number represent?

The number of protons in the nucleus

What does the 1-7 columns represent

The seven energy levels (or electron shell)

How about helium? There is a 2 to its symbol's left. 2 electrons. Where do they go?

They both go into the first energy level.

Take a look at Potassium (19) on the Electron Configurations chart. It does something that you might not expect: it s got 2 electrons in the 1s, 2 electrons in the 2s, 6 electrons in the 2p, 2 electrons in the 3s, 6 electrons in the 3p (OK, so far so good) but then it puts its last electron in the 4s orbital! What the heck is going on?

an s orbital is a very low energy orbital (think of a door made out of a piece of paper; it would be very easy to walk right through!) a d orbital is a much higher energy orbital and it requires a lot more energy to get an electron into it (think of an oak door). So it actually requires less energy for potassium to get its last electron into the 4s (even though it s going into a higher energy level) than to get it into the d orbital of the 3rdenergy level

Schroger and his colleagues thought the Bohr's planetary model of the atom was a fine piece of work, but it wasn't complicated enough to reflect the true nature of the

atom

Electron Dot Notation is a method used in Chemistry to indicate the number of electrons that are in an entire outer

electron shell or energy level (not just the outer orbital but the whole outer shell).

Today, we call these paths

energy levels or electron shells

.Calcium (20) does that too it puts its last 2 electrons in the 4s. We don t start backfilling the 3d until we get to Scandium (21).

hmmmm

Number of Electrons equals? (2 things)

number of protons which also equals the atomic number

Note what happens when you jump up to a higher shell or energy level: you start right back with another what?

s orbital

We identify these little guys with little letters :

s, p, d, f

A neat short-hand way of indicating where electrons are not only in which shell or energy level, but also in which orbital, is called the

the Electron Configuration Notation

). Outer shell electrons (also known as

valence electrons

Why are valence electrons so important in chemistry?

very important in Chemistry because they have so much to do with determining the properties of elements

When we are talking about energy levels we use numbers ? to identify them.

(1 -7)

The p orbital, which has sort of an hourglass shape, has three orientations explain

(px: p for the shape and x because it s straddling the X axis, py: p for the shape and y because it s straddling the Y axis, pz: p for the shape and z because it s straddling the Z axis)

So the next step was to say that within the energy levels (or electron shells)

) are sublevels (or orbitals

The s orbital has 1 orientation and can hold a maximum of ? electrons The p orbital has ? orientations and can hold a maximum of ? electrons The d orbital has ? orientations and can hold a maximum of ? electrons The f orbital has ? orientations and can hold a maximum of ? electrons

1 : 2 3:6 5:10 7:14

Lithium has 3 electrons. We always start at the beginning and that s the first energy level. It only has an s orbital and it only holds 2 electrons. It always fills up first. When it s full, we move to the 2nd energy level and we always start over with another s orbital when we move to a higher energy level. So lithium s electron configuration notation is:

1s to the 2 2s to the 1

Let s try Helium

1s2 First energy level, s orbital, 2 electrons.Read it backwards, it makes sense that way too: Helium has 2 electrons in the s orbital of the 1st energy level

Beryllium has 4 electrons.

1s22s2

Boron has 5 electrons. We are going to stay in the 2nd energy level we have filled up the s orbital there with 2 electrons so boron s last electron will go in the p orbital of the 2nd energy level:

1s22s22p1 or it can also be written 1s22s2p1 (I like to write that second 2 before the p just to reiterate that I m still in the 2nd energy level

Now that we re in the p orbital of the 2nd energy level, we re just going to add an electron to the p until we fill it up with 6 electrons (and consequently fill up the 2ndenergy level with 8 electrons total. 2 in the s and 6 in the p. So Carbon (with 6 electrons) would be

1s22s22p2

Neon (with 10 electrons) would be

1s22s22p6

Sodium (with 11 electrons) would be

1s22s22p63s1since we filled up the 2ndenergy level with 8 electrons now we move on to the 3rd energy level and start right back with an s orbital

Let s try Aluminum with 13 electrons.

1s22s22p63s23p1

How about Argon with 18 electrons?

1s22s22p63s23p6

The K shell (or 1st energy level) only contains an s orbital Maximum number of electrons in the K shell

2

maximum number of electrons in an s orbital also =

2 and that s why the K shell can t hold any other orbitals they wouldn't fit!

K = 1 so we re going to use the number 1 for our n. 1 X 1 = 1, 1 X 2 = 2. The first energy level or the K shell can hold a maximum of ? electrons

2 electrons.

Now jump down to sodium. 11 electrons.

2 in the first energy level that fills it up, the next 8 go into the second energy level ,remember that the second energy level has a maximum of 8, so the last electron has to go into the third energy level.

Each energy level (electron shell) has a different capacity of electrons they can hold different maximum numbers of electrons. To calculate their maximum capacities, we can use a very handy formula:

2n2 = Where n = the number or energy level. Here s how it works: first, take the number of energy level and square it (multiply it by itself), then multiply that answer times 2

So an atom has how man dimensions?

3

The d orbital has different shapes and ? many orientations The f orbital really has a bunch of different shapes (I don t have them illustrated here but you've got to trust me on this!) and has seven orientations

5

Maximum number of electrons in an s orbital = 2, maximum number of electrons in a p orbital =

6, 2 + 6 = 8

The f orbital really has a bunch of different shapes (I don t have them illustrated here but you've got to trust me on this!) and has ? many orientations

7

L = 2 so we re going to use the number 2 for our n. 2 X 2 = 4, 4 X 2 = 8. The second energy level or the L shell can hold a maximum of ? electrons.

8

The L shell (or 2ndenergy level) contains both s and p orbitals Maximum number of electrons in the L shell =

8

OK, let s start with hydrogen. By looking just to the left of H we see a 1. That means that hydrogen has an atomic number of 1 (one proton) and because it is neutral it also has one electron. Where does that one electron go?

? It goes in the first energy level (there it is under the 1). Does that make sense? Sure. Remember, the first energy level is the one closest to the nucleus and it requires the least amount of energy to get an electron into it.

Explain the Pauli Exclusion Rule

Any orientation can hold a maximum of 2 electrons and if it does hold its maximum of 2 electrons, the electrons have to be spinning in opposite directions (think clock-wise and counter clock-wise)

What does the number to the left of each element represent on the Electron Config Elements Chart?

Atomic Numbers

Number of protons equals?

Atomic number

WHy does it become positively charged?

Because it lost an electron which is negatively charged and now the positively charged protons outnumber the electrons

Why are atoms not electrically charged?

Because they have same number of electrons as they do protons. (So I guess that means you know how many electrons they have by their atomic number)

The Sixth Series is made of all the elements that have all of their electrons completely contained in the first 6 energy levels. Begins with

Cesium (55) Rodon (86)

The s orbital has a spherical shape (take a look at the following diagram what tells you it s supposed to represent a sphere rather than a

Circle

? Hmmmmmmmm. Let's see, there is an X axis, there is a Y axis those are all you would need for a two dimensional circle ..but wait, what s that crazy Z axis doing there? Representing the third dimension, that is what!

Depth

Actually, Schroger and his colleagues said that whatever the number of energy level is, it will have that many what?

Different orbitals

The Seventh Series is made of all the elements that have all of their electrons completely contained in the first 7 energy levels. Begins with and who know where it will end??? This is where the new elements that are discovered (synthesized in labs is more like it) go.

Francium (87)

The simplest element in the whole universe

Hydrogen

The First Series is made up of all the elements that have all of their electrons completely contained in the first energy level. Take a look at the Electron Configuration chart. There are only two elements that fit this criterion:

Hydrogen and Helium

What happens if you remove a proton from the nucleus of an atom?

It becomes a different element

The first energy level that is the one that is closest to the nucleus and has the lowest energy

K

When we are talking about electron shells we use letters ? to identify them.

K-Q

The second energy level is a bit further from the nucleus

L

The Second Series is made of all the elements that have all of their electrons completely contained in the first 2 energy levels. Look at the chart: the second series begins with ?and it ends with ?

Lithium (3) Neon (10)

The third energy level is a little further out still and so on.

M

M = 3, 3 X 3 = 9, 9 X 2 = 18 N = 4, 4 X 4 = 16, 16 X 2 = 32 O = 5, 5 X 5 = 25, 25 X 2 = 50 P = 6, 6 X 6 = 36, 36 X 2 = 72 Q = 7, 7 X 7 = 49, 49 X 2 = 98

M= 18 N= 32 O = 50 P = 72 Q = 98

Number of neutrons equals?

Mass number - atomic number ( I think it is the same as the protons too)

came up with the idea that electrons move in particular paths around the nucleus of an atom

Neils Bohr

What happens if an atom looses or gains electrons? Does it become a different element?

No it doesn't become a different element, it becomes an ion (an electrically charged atom)

Do atoms have an electrical charge?

No.

The Fourth Series is made of all the elements that have all of their electrons completely contained in the first 4 energy levels. Begins with ends with ?

Potassium (19) Krypton (36)