Atoms, Molecules, & Elements Essay

The students created a macroscopic, three-dimensional (3D) model of several properties of the periodic table. They explained in their own words the following terms: atomic radii, ionic radii, first ionization energy, and electronegativity. Lastly, they identified, described, and explained the patterns observed in the 3D periodic tables for the following element properties: atomic radii, ionic radii, first ionization energy, and electronegativity.

Every now and then one atom gains enough energy to break free from the group. This is called a vapor.

11. Think and discuss: Select the PERIODIC TABLE tab, and look at the second row, or period, of the table. How does this row reflect the subshells of the second shell?

-Dmitri Mendeleev- first periodic table, organized 63 known elements according to properties, organized into rows and columns and wrote name, mass, and chemical properties on each

Atoms make up molecules, which make up cells. Cells are the base of everything that is living. Cells make up tissues, when a group of cells are similar in their structure they group together and make up the tissues. When two or more tissue types combine, it creates an organ that has a specific functionality for the

It takes very little energy to break these forces; therefore simple covalent compounds have very low melting points and generally appear as gases. You can also get multiple bonds; this is where atoms can share more than 2

Around 2,500 years ago, Democritus and his partner Leucippus were the first ones to develop the atomic theory in written history. Their theory proposed that every kind of matter was made up of tiny particles, which were named atomos, which means that it is indivisible. This meant that Democritus and Leucippus thought there were little particles of everything, but, the next breakthrough in atomic theory wasn’t made until the early 1800s with a french chemist by the name of Antoine Lavoisier, he was the one who came up with the idea of the law of the conservation of mass, which states that matter stays the same even when it changes shape or form. Then, James Dalton said that all matter was made up of atoms, which were indivisible, and unbreakable.

There has not been safety professional at Podunk University for a year and half, leaving the prestigious university to fend for itself in the world of safety. Since no one was actively filling this position, the subsequent safety professional will have a lot of catching up to do. The primary focus of the safety professional will be the hazardous material and hazardous waste issues on the campus. While conducting the preliminary tour of the campus, it is noticed that there is a lot of issues that are effecting safety around the campus. The biology department and the chemistry department will need to have all chemicals inventoried to include hazardous waste. The physics department’s use of high voltage and the use of lasers in their department. The automotive technology department has more than a few issues that will need to be addressed while developing the safety program. The last major issue that was identified was the Massive Arena, the building is one of the oldest buildings on campus and is currently under renovation. The problems with many older buildings is the presents of asbestos insulations and the dangers that it presents even while being removed.

The noble gases are the gaseous elements helium, neon, argon, krypton, xenon, and radon, in group 18 of the periodic table. Additionally, they are considered the most unreactive of the elements, due to the fact that the valence electrons are all “full”, thus making the group the most stable, as well. When it comes to the periodic trends, the noble gases have the some of the lowest densities because they are gaseous elements, meaning they state of matter consisting of particles that have neither a definite volume nor definite shape. The lack of electronegativity of the noble gasses is based off of their group, which already has a full outer shell, meaning they do not attract any electrons.

Other elements depending on the cells by types and domains (discussed above) vary and together they form compounds (Simon, Dickey, Reece, & Campbell, 2013). The ways elements develop formations to create compounds are called bonds and the bonds are Molecular and Chemical. There are 2 types of Molecular bonds where Ionic bonds form by attracting oppositely charged ions and Covalent bonds form by two atoms sharing one or more pair of negatively charged subatomic particles (Electrons). Chemical bonds such as Hydrogen bonds occur through the changes in chemical composition of matter which are called chemical reactions. The difference between covalent (molecular) and chemical bond is that in chemical bond, the electrons are not shared among particles but the particles just orient themselves together similar to the attraction of magnetic polarity to create a bond. All types of bonds, Ionic (e.g. NaCl – Salt), Covalent (e.g. O2 – Oxygen), and Chemical (e.g. H2O – Water) contribute to the composition of cells that are necessary to sustain life.

into the blood. Doctors would measure the amount of tracer that is found in the urine of their patient in order to diagnose them. Which is the only subatomic particle that is directly involved in the chemical reactions between atoms? The only subatomic particle that is directly involved is an electron. What is potential energy? Potential energy is energy that matter has due to its location or structure. Explain which has more potential energy in each pair: boy at the top of a slide/boy at the bottom Boy at top of a slide because of his location. electron in the first energy shell/electron in the third energy shell Electron in third energy shell because of its relative distance from the nucleus water/glucose Glucose because of its structure (glucose has more chemical bonds) What determines the chemical behavior of an atom? The distribution of electrons in the electron shells determines the chemical behavior of an atom. For sodium: How many valence electrons does it have? 1 valence electron How many protons does it have? 11 protons Section 3 15. Define molecule. A molecule is formed by two or more atoms held together by a covalent bond. 16. Now, refer back to your definition of a compound and fill in the following chart: Molecule? Compound? Molecular Formula Structural Formula (y/n) (y/n) Water Yes Yes H2O H - O - H Carbon Dioxide Yes Yes CO2 O = C = O Methane Yes Yes CH4 Oxygen Yes No O2 O = O What type of bond is seen in O2? Explain what this means. A double covalent bond is

Why do chlorine and sodium have charges after electron transfer? Sodium atom lost an electron now it has a positive charge because the protons are greater than electrons. Chloride gains the electron so there is a negative charge because electrons are greater than protons.

Stanislao Cannizzaro was born on July 13, 1826. When he was younger, he showed great skills in mathematics. He later became an assistant to Rafaelle Piria. Cannizzaro saw his dedication to his work that Piria influenced him to transform his study to chemistry. Cannizzaro later determined the different atomic weights. Dmitri Ivanovich Mendeleev always had a love for history, math, and physics. He attended the University of St. Petersburg where he formed the ideas of chemical compounds. Mendeleev found out that you could simplify the periodic table by separating them into different groups. He arranged them by the atomic weights and then later realized they had similar chemical properties. He had also given predictions of future elements and their properties.

| Secondary quantum number, l: the electron sublevels or subshells; tells you orbital shape (0 to n-1)

The atoms of each element possess a unique electron configuration because of the fact that different elements have different numbers of electrons. The ground state electron configuration shows both the lowest and most stable position for each element. There are three basic rules used for determining the ground-state electron configurations.