Weekly Assignment 10/27

This week in chemistry we started going into Unit 3, which is all about the periodic table. The periodic table was first arranged by Dimitri Mendeleev. He grouped the elements in columns by similar properties and in order by increasing atomic mass. Dimitri Mendeleev also predicted the properties of several elements before they were even discovered, based off of his prior knowledge and understanding of his table. Today's modern periodic table has the elements grouped by similar properties in the same column or group. Unlike Dimitri Mendeleev's periodic table, the modern periodic table is ordered based off of increasing atomic numbers. These atomic numbers on the periodic table are determined by Henry Moseley. The horizontal rows of the periodic table are called periods, and there are 7 periods total. The vertical columns on the periodic table are called groups, and groups contain elements of the same or similar properties. 

Metals

• good conductors of heat and electricity
• have luster
• are malleable and ductile

Nonmetals

• brittle as solids
• can be gases
• can be liquids
• nonconductors
• nonlustorous

Semi-Metals

• have properties from both metals and nonmetals 

The periodic table has four different blocks, the S block, the D block, the P block, and the F block. In the S block you can find groups 1 and 2, which are Alkali metals and Alkaline earth metals. The D block contains all of the transition metals and has groups 3-12. The P block contains all of the non metals, such as the metalloids, hallogens, and the noble gases and it has groups 13-18. The F block contains all of the inner transition metals. 

In class we did a lab that was supposed to help us better understand the periodic table and how the elements are arranged in the periodic table. We were given elements with their names and all of their properties and we had to arrange them how they are on in the periodic table. Then we were given some elements that had all of its properties but no name. We had to look at the elements properties and determine where it was located on the periodic table and what its name was. Not only did we have to locate where it was on the periodic table, but we also had to explain why we thought it belonged in the place that we put it and why we thought it was a certain element. This experiment really helped me understand how exactly the periodic table was set up and how you can tell what an element is based on its properties and the properties of the elements around it. 

Also, to help us better understand the periodic table, we had to take a blank table and color it according to what the different groups and elements were. We had to label all of the groups and periods. Then we had to outline the different blocks, like the S block, D block, P block, and F block. Then we had to color accordingly. Group 1 was colored purple. for the alkali metals. Group 2 was colored pink for the alkaline earth metals. Groups 3-12 were colored blue for transition metals. Group 17 was colored green for hallogens. Group 18 was colored dark pink for noble gases. This coloring assignment helped us better knowledge ourselves on which groups contained which types of elements. 

Weekly Assignment 10/17

An atom is made up of a nucleus holding a certain number of positively charged protons and neutrally charged neutrons. This nucleus is surrounded by a cloud of negatively charged electrons. The charge that holds these protons and electrons together is called a electromagnetic force. This force holding them together also tries to push the protons apart and that is where the neutrally charged neutron comes into play to keep the protons from pushing away from each other in the nucleus. Each atom has a specific number of protons and this number is what determines the element that the atom is. The protons also determine the Atomic number of an atom and sometimes the electrons if the atom is neutral. To find the mass number, you add together the neutrons and protons, and to find the neutrons you subtract the mass number and the proton number. An atom is called an isotope when it has different mass numbers. When an atom has different mass numbers then it can have different neutron numbers as well. Ions are atoms that gain and lose electrons. When an atom gains an electron it is called a cation, and when an atom loses an electron it is called a anion.

If you want to pull an an atom apart, you have to start with the electrons. There are many ways that you can pull an atom apart, some ways being shining a light on the electrons to push them apart, or exposing the electrons to another electromagnetic force. There is also many other ways to pull an atom apart but the main thing that will do the trick is heat. The heat makes the atoms move around and hit each other. The first electron will be easy to strip apart, but then as the electrons go on, it gets harder to pull apart. Once all the electrons are gone, you are left with just a nucleus. The process of stripping apart the nucleus is pretty much the same exact process of stripping apart the electrons. Even though I just talked about this long process of pulling apart an atom, you can also easily just hit it hard enough with something firm and it will break the atom apart into tinnier bits and pieces. Once breaking apart an atom, you can find that electrons are made up of even smaller parts called quarks. Quarks are held together by the same extremely strong force that hold the nucleus together. Also a fun fact about pulling apart an atom is that if you hit an atom hard enough, you might find even more bits and pieces of energy particles that you didn't know was there before!

Albert Einstein believed that atoms bounce off of each other in a way that's called Brownian Motion. He also believed that the mathematical equation for the Brownian Motion is evidence of the existence of atoms. He also concluded that you can determine the size of an atom based on how they move around.