Science: Atom & Molecules

Over the course of the last 5000 years, mankind’s knowledge has been constantly advancing. Chemistry, a branch of science, has experienced a tremendous leap and expansions since ancient Greek civilization. One of the major breakthroughs in the advancement in Chemistry was the creation of the Atomic theory, which laid a foundation for the modern-day Chemistry and future of science. The Atomic theory introduced the idea of atoms, which are defined as the discrete units of matter. There are five key scientists that significantly contributed to the Atomic model over a span of thousands of years. They are: Democritus, John Dalton, J.J. Thompson, Ernest Rutherford, and Niels Bohr.

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

Like "helium-three" would be used for a helium atom that has three nucleons. We write the number of nucleons to the upper left of the abbreviation such as this one: 3He. We write the charge on an element or electron to the upper right of the abbreviation such as this one: E-. Hydrogen has three isotopes: normal Hydrogen is 1H, with not anymore than one proton. Deuterium is 2H, which has just one proton and a neutron. Tritium is 3H, which has one proton and two neutrons. Tritium is unstable. It is radioactive, spitting out a fast electron as it disintegrates into helium like this example: 3H ------> 3He + e-. A balanced equation has the same "net" charge and mass on the left side as it has on the right side. Everything is the same on the two sides, just arranged differently. There are three types of radiation: alpha particles are high speed helium nuclei (4He+2) which can only be stopped by a piece of paper or skin. Beta particles are high speed electrons (e-) which can pass through paper, but not to much paper though like a book. Gamma rays are not particles at all. They are very high energy light rays that can only be stopped by very thick and big materials such as Hevesy bricks. Radiation can harm you if you get hit by too much of it, so watch out! So lastly there is many ways to find the atomic mass, on how they describe elements and different parts there are is in them. Protons, electrons and neutrons,

As early as 400 BCE atoms were believed to be the building blocks of all matter. The atom is made up of three subatomic particles protons (p+) , neutrons and electrons ( e-). Protons have a positive charge and can be found in the nucleus along with the neutrons who have no charge. Protons, along with electrons, tell you the atomic number of any given element. A positron is the opposite of an electron and contains the same mass and spin of an electron but they have a positive charge. The sum of the number of protons and neutrons equals the mass number. The mass number connects matter to it’s antimatter, they are equivalent in value while the charges are opposite. This attraction cause the corresponding matter particles to annihilate each other.

Elements are made up of their atomic structure, which has protons, neutrons, and electrons that help make it up. The protons and neutrons are in the center of the atom, and the electrons are outside of the nucleus. The protons and neutrons have 1 amu and the electrons have no charge. The protons are positive, neutrons have no charge, and electrons have a negative charge.

Chemical bonding is responsible for the strong mutual attraction, which prevails between atoms. Atoms are the basic buildings blacks for all types of matter. Atoms are capable of joining together to form molecules, which are responsible for forming most of the objects around us. Atoms forms chemical bonds because lone atoms are extremely reactive and unstable; they form bonds to achieve stability. Our world is made up by so many different elements, and they are responsible for combining together in thousands of different arrangements, in different states of matter, because of a process called chemical bonding. Many atoms, through the process of chemical bonding, lose a few extra electrons to integrate with the octet rule.

J.” Thomson, OM, FRS of Great Britain received the 1906 Nobel Prize in Physics for his discovery of the electron and for The Thomson’s atomic model. He assumed that the body of an atom is a spherical object containing N electrons confined in homogeneous jellylike but relatively massive positive charge distribution whose total charge cancels that of the N electrons. It was sometimes nicknamed as plum pudding model, because of its features as you can see below.

Compounds are formed by combination of atoms in simple ratios to give compound atoms.” The theory was the basis of modern chemistry Dalton’s theory provided a basis for understanding the results of earlier experimentalists, including the The Law for Conservation of Matter and the Law of Constant Composition, which stated all samples of a substance have identical elemental compositions. These theory’s and experiments defined the concept of chemical reactions.

Let us think of atoms in a molecular formula as building blocks. __Molecular formulas__ tell us how many atoms of each element there are in a molecule. Just like the building blocks, these atoms can be bonded together in different ways.

Atoms of different elements can be combined to form compounds. Atoms of the compounds are present in the same relative numbers.

It’s atomic symbol according to the Periodic Table fo the Elements, H was the atomic symbol that represents hydrogen the element. Hydrogen’s average mass of the atom was 1.00794. It’s density was 0.00008988 grams per

Helium is an element. It is in the first period, in group 8 in the periodic table of elements. Helium is also a nonmetal. Its element symbol is He, and it has an atomic number of 2, and an atomic mass or molar mass of 4.003 amu. This means that helium contains 2 protons, 2 electrons, and 2 neutrons. Helium is the second most common element on the universe.

Atoms are the smallest, and are considered to be the most basic unit of the universe because they are found in all living and nonliving things. They are made of protons, neutrons, and electrons. There are different types of atoms, but carbon, nitrogen, hydrogen, and oxygen atoms are the more common atoms. Atoms bond together to form molecules, which are also found in both living and nonliving things. For example, if two hydrogen atoms were to bond along with one oxygen atom, they would form one water molecule, hence the chemical formula H2O. Cells are known as the most basic unit of all living things, unlike atoms and molecules. Cells, of course, are made of atoms and molecules. Though it is clear that cells, molecules, and atoms are alike in some ways, their differences are much more

1. Write the complete symbol and determine the no. of electrons, protons and neutrons of the following

The ancient Greek the word atom means indivisible. It was used to describe the smallest indivisible piece of a matter. He believed that all matter could be broken down using femtometers. Atoms were perceived to be indestructible. Atom was derived from the greek word atomon or atomos meaning indestructible. This fundamental atomic theory was developed by a scholar named Democritus. He was a pupil of the famous philosopher Leucippus. From Democritus’ original Atomic Theory much has changed. The probability that a scientist with such primitive technology could devise an accurate atomic theory is vastly unlikely. Due to the efforts of many great scientists over the years more is known about the atom and the Atomic Theory has developed greatly.