All About Atoms (7th)

Our first unit this year is Chemistry and we start by reviewing what they learned in 5th grade. So, we review the parts of an atom! We then add a little more to it and learn all about atomic models and the atoms of different elements.

In our notebooks, we created a timeline (to scale) for developments of different atomic models. They do have to know the different scientists we discussed and the contributions of each. The timeline includes a foldable we filled out to help them remember the different scientists.

We then reviewed the location and charges for protons, neutrons, and electrons. We filled out another foldable. I found the idea on another teacher's site and then used Publisher to make one for us! We went through everything together and they filled it out. We'll get it glued into our notebooks, but they need it for homework right now.

For their homework, they need to know how to calculate the mass number, atomic number, and the number of protons, neutrons, and electrons. Here are the instructions we went over in class:

• Mass number = # protons + # neutrons
• Atomic number = # protons (they are always the same number!)
• Protons = atomic number (see above) OR Protons = mass number - # neutrons 
• Neutrons = mass number - # protons
• Electrons = # protons OR atomic number

For example: Iodine has a mass number of 127 and an atomic number of 53. So, Iodine has 53 protons (atomic number), 53 electrons (# protons), and 74 neutrons (127 - 53).

We also started learning how to draw Bohr diagrams and Lewis dot structures. A Bohr diagram shows all the electrons that an atom has; whereas, a Lewis dot shows only the valence, or outermost, electrons. In a Bohr diagram the energy levels are shown as rings around the center and the electrons are added to each ring until the energy level is full. This is the Bohr model for an element with 11 protons and 11 electrons. Notice that the first energy level has the only 2 electrons it can hold spaced as far apart as possible because like charges repel. The second energy level will have the electrons spread as far as possible for the first 4, then the electrons start pairing up (this has to do with orbitals-the s, p, and ds that are outside of what we cover in 7th grade). The electrons continue filling the 2nd level until it contains all 8 it can hold, then start filling the 3rd level. We won't have more than 3 energy levels for this class. Also, we have not yet started discussing the periodic table, so students do not need to try to figure out which element this would be.



The Lewis dot structure would be easier to draw because it only shows the valence electrons. These are the outermost electrons an atom has. It is important to be able to tell how many valence electrons an atom has because these are the electrons that are involved in chemical bonds and atoms will react in certain ways with other atoms based on the number of valence electrons. For now, students will determine the number of valence electrons an atom has by looking at the Bohr diagram (we will learn how to do that using the periodic table, but that comes later). For the atom above, it would look like this:

Calculating Speed

Speed = Distance / Time

This is fairly straight forward. If you are given a distance (km, m, or some ridiculous unit such as miles) and a time (hr, min, sec); you simply divide the distance by the time. The unit for speed would be km/hr, m/s, or something similar (we here mph very often which is miles/hr).

Trying to determine how far an object will travel and how long a trip will take can be simple as well. You could do a little algebra and rearrange your variables or you can remember our simple triangle.











We glued one into our notebooks! The triangle will give you the equation you need if you simply cover up the measurement you are looking for. Looking for the distance? Cover up the D and you get Speed x Time, so D = S x T. Time? Cover up the T for Distance / Speed or T = D / S!

Example:

1. Ms. Walls is running away from zombies at 3 m/s. If safety is 60 m away, how long will it take Ms. Walls to reach safety? Since we are looking for a time, our equation is  T=D/S, now we fill in the information we are given.
• T = 60 m / 3 m/s (since we have m on top and m on bottom, our unit cancel and we have s)
• T = 20 s
• Does this make sense? Double check your number and units! 

Always pay attention to the units you are given and the units you are asked to give your answer in.

1. Snoopy has flown his doghouse 15 km and it has taken him 30 min. What is his speed in km/hr? The easiest way to solve this is to convert 30 min to hr. Since there are 60 min/hr; divide 30 min by 60 min/hr to get 0.5 hr. Then, find the speed. S=D/T, so S= 15 km / 0.5 hr = 30 km/hr.

 

Speed and Velocity (8th)

Speed is a rate, or a number that tells us how fast something happens. In this case, it tells us how fast a distance is traveled. For example, if someone rides a bike 2 m/s, they are traveling 2 meters every second. We could use that to track how far they have traveled for a certain amount of time or how long it would take them to arrive at a destination. We often here speed measured in mph or miles per hour; which would tell us how far someone would get if they traveled for an hour at a constant speed.

There are two types of speed. We could look at average speed, the total distance traveled / total time it takes. Average speed would be what you calculate for a race or road trip: John traveled 12 km to the store and it took 20 min to get there. We simply look at how far he traveled and how long it took. Stoplights, changes in speed, etc don't matter here. Instantaneous speed is a measure of how fast on object is traveling at a given instant in time. For example, if you get pulled over for speeding, the cop tells you how fast you were traveling when he caught you with his radar.

Velocity is similar to speed, but it has a direction. Two ways to change velocity are to change speed or change direction. Objects very rarely have a constant velocity for long because objects usually change speed or direction frequently.

Science Notebooks

We have spent quite a bit of time, but we have our notebooks all set up and ready. I made some changes from last year. Notebooks are still going to be an essential part of learning, but I've made some improvements that will help us better (I hope).

The first 2 pages are for the table of contents, which is 3 columns, Date, Title, Page #. The front cover also has the expectations and the rubric I will use to grade notebooks.

There is also an index at the back, this is used to put words and ideas in for reference, not to define words, but I may try that later. There is also a ribbon bookmark and a large envelope taped into the back for unfinished work. We haven't used the bookmark yet, but I can have them mark the page an assignment I need to grade is on, so I don't have to search for it. I hated that last year.

Each section is marked with a divider tab on the top of the notebook. I just used a 1.5"x1.5" piece of construction paper and packing tape, it seems to be working. We have a section at the beginning for "Nature of Science" and one at the back for "Bellwork." The units will each have their own section too.

 At the beginning of each unit we design a cover page. This is mine :) They do lots of drawing or graphic representations, but they get graded on their use of color, their creativity, and their effort; NOT ability. Most cover pages we have a very specific design based on what we will study, but the ideas and creativity is theirs.

 Within the sections, all notes and labs are started on the left hand page. Right hand pages will be for pictures, graphic organizers, handouts, and data.

Metric Conversions

We have been spending a lot of time going over the metric system, different tools of measurement, and how to use those tools. We learned about metric conversions yesterday and today. Students have a practice worksheet on how to convert metric units. The worksheet will be due Tuesday, this allows them to work on it tonight, ask questions tomorrow and go home to finish it. They need to start on it tonight because it is due Tuesday, so they won't have time to finish it on Tuesday.

We set up a chart in our notebooks that looks like this:

They have the 6 main prefixes will use, the abbreviations, and what number they stand for. I teach in like a ladder or staircase. When you go right down the staircase the units get smaller, so you move your decimal to the right. If you go left up the staircase the units get larger, so you move the decimal to the left.

So, you start by right the number given WITH a decimal where it belongs. Then, you look at the chart and decide which direction to move and how many steps. Next, you move the decimal that many spaces in the correct direction. Draw the new decimal, fill in any empty spaces with zeros, and rewrite the correct number with units (a number without a label is complete nonsense).

Class Curriculum

7^th Grade Science Curriculum:

            1^st Semester:

·         Unit 1: Chemistry

o   Structure of Atoms and the Periodic Table

o   Chemical Bonding and Reactions

·         Unit 2: Genetics

o   Cell Growth and Division

o   Gregor Mendel and inheritance

o   Understanding chromosomes and genes

2^nd Semester

·         Unit 3: History of Earth and Life Forms

o   Paleontology

o   Geologic Time

·         Unit 4: Evolution

o   Evolution and changes in populations

o   Natural Selection

o   Extinction and Speciation

·         Throughout the year we will look at different scientists, branches of science and the nature of science.

 8^th Grade Science Curriculum

            1^st Semester

·         Unit 1: Physics

o   Motion

o   Forces

o   Density and Buoyancy

o   Work

o   Energy

o   Power

·         Unit 2: Electricity and Magnetism

o   Electricity

2^nd Semester

·         Unit 2 continued

o   Magnetism and Electricity

·          

·         Unit 4: Waves

o   Wave properties

o   Types of waves

o   Features of waves

·         Unit 5: Electromagnetic Radiation and Light

o   Waves of the electromagnetic spectrum

o   Mirrors

o   Eyes

·         Unit 6: Sound Waves

o   Speed

o   Frequency and pitch

o   Amplitude and loudness

·         Unit 7: Chemistry of Food and Respiration

o   Flow of energy

o   Photosynthesis and respiration

o   Human nutrition and health

·         Throughout the year we will look at different scientists, branches of science and the nature of science.

Welcome

Welcome to another year! This week we are spending our time getting everything ready for our new year. We are getting our Science notebooks put together; these are a really big deal. I use them for everything and we put so much stuff in there, so we set them up a certain way to make sure we have an efficient system.

We will also be going over lab safety rules and symbols. This is REALLY important because I want everyone to be safe during our lab activities. Anyone that breaks any rules will be sent out of lab immediately and receive a zero on the assignment. When safety is at stake, I only have one consequence. I have some great labs planned and I know the students will enjoy them, so I don't anticipate any problems.

Also, I know that it can be harder to get your volunteer hours in when your kids are in middle school and we don't ask for parent help as much. However, if you need hours, feel free to contact me. I'm sure I can find something I need help with. Especially, if you don't mind doing some computer work or organizing in the classroom to help us out.

And because you've asked, here are some pictures :)

I am looking forward to a great year!