Atomic Theory

Concept 2.1 Matter consists of chemical elements in pure form and in combinations called compounds

13. What are the subatomic particles and what is the electrical charge of each? Protons (positively charged), Neutrons (electrically neutral), both found in the Nucleus of the atom & Electrons (negatively charged). Where in the atom is each of these particles found? In the orbital (Electrons)

In this experiment, you will have a chance to test the hypothesis that Ernest Rutherford used when determining the size of the nucleus. In his "gold foil experiment," Rutherford shot alpha particles at gold atoms. Once he realized that the alpha particles were hitting a concentrated positive mass, he developed the nuclear model of the atom. Next, he set out to determine the relative size of the nucleus compared to the rest of the atom. He reasoned that the smaller the nucleus, the less likely it was to be hit by an alpha particle. This led to a simple comparative ratio:

We can use the small numbers to give information about the particles in the nucleus.

1. An Element is a substance that cannot be broken down to other substances by chemical reactions, while a compound is a substance consisting of two or more different elements combined in a fixed ratio.

44 - Identify the element (whole name and abbreviation) based on the atomic number and atomic mass:

___________________________________________________________________ ___________________________________________________________________ 8. _______________ is 2protons and 2 neutrons and has little penetration power? 9. _______________ is an electron and its’

What is the atomic structure you may ask? Well, it’s the law stating the structure of an atom. It is composed of a positively charged nucleus containing a certain amount of protons (positive), neutrons (neutral charge), and electrons (negative). The amount of each subatomic particle (proton, neutron, and electron) all depend on what the element is. Now although this statement may seem fairly simple it was most definitely not. People have been studying the atomic structure for more than 300+ years and are still studying it. So after reading this you may wonder who even made this atomic structure up. After hundreds of years of research there is not any one individual who made the structure up but roughly

The first three ionization energies of an element are 570, 1175 and 5950 kJ*mol-1. What is the most likely formula for a stable ion of ?

Multiple forms of the same element that have the same amount of protons but different number of neutrons in their nuclei.

6. I’ve got the 2nd highest number of protons in my group. Who am I?

Technetium 99m in isotope notation is 99m43Tc. 99 being the mass number and 43 being the atomic number.

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

they differ in the number of neutrons in each atom, the atomic mass, & their nuclear stability

An Atom is the the basic building block of all matter. Atoms are made up of Particles, called: Protons, neutrons and Electrons. Protons carry a positive charge, the neutron carry 's a neutral charge and the electron carry’s a negative charge. The Atom has two main parts the Nucleus and the Electron Shell. The Nucleus contains the Protons and Neutrons. The electron Shell Contains the The electrons.