Matter at Atomic Scale, Diapositivas de Química

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STAGE 2:

Matter at atomic scale

M.A. Leilania Lizeth Gómez Ruiz

Universidad Autónoma de Nuevo León

CIDEB

Competences

 GENERAL COMPETENCES:

8. Uses methods and techniques from traditional and new researches for

developing his academic work, the exercises of his profession and the

generation of knowledge.

 (^) Understands in a reflective way the stages to achieve his goals.  (^) Formulates and makes conclusions based on the evidences obtained.

 GENERIC COMPETENCES:

5. Develops innovations and proposes solutions based on established methods.

 (^) 5.3 Identifies the systems and rules or core principles that lead to a series of phenomena.  (^) 5.5 Synthesizes evidences obtained from experimentation in order to make conclusions and formulate new questions.

 DISCIPLINARY COMPETENCES (EXPERIMENTAL SCIENCES):

1. Establishes an interrelation between science, technology, society and

environment in particular, historical and social contexts.

11. Analyzes general laws governing the function of physical environment and

appreciates the human actions of environmental impact.

14. Applies safety standards to handling of substances, instruments and

equipment in his daily life activities.

• (^) Pure substance that cannot be broken down into simpler substances by physical or chemical means. Element
• (^) The smallest particle of an element that retain all the properties of that element.
• (^) Is electrically neutral, spherically shaped and composed of electrons, protons and neutrons. Atom

Elements in nature  118 elements are known 88 of them are found in nature  The rest of them are not found in nature and have only been synthesized in the laboratory. LIQUID STATE

• (^) Bromine Br
• (^) Mercury Hg GASEOUS STATE - (^) Hydrogen H - (^) Nitrogen N - (^) Oxygen O - (^) Fluorine F - (^) Chlorine Cl - (^) Helium He - (^) Neon Ne - (^) Argon Ar - (^) Krypton Kr - (^) Xenon Xe - (^) Radon Rd SOLID STATE - (^) Rest of the elements

Subatomic particles

• (^) All atoms are made of three fundamental subatomic particles: the electron, the proton, and the neutron.
• (^) Atoms are spherically shaped.
• (^) Atoms are mostly empty space, and electrons travel around the nucleus held by an attraction to the positively charged nucleus.
• (^) https://www.youtube.com/watch?v=yQP4UJhNn0I

Atomic number and Isotopes  Atomic number: the number of protons in an atom.  Mass number: total number of protons and neutrons in the nucleus.  Isotopes: atoms with the same number of protons but different numbers of neutrons. Z = atomic number = number of protons in an atom= number of electrons A = mass number = the sum of number of protons and neutrons in the nucleus. Neutron number= A - Z

Challenge problems

ATOMIC MASS: 24.31 amu Solve Exercise 4.44 page 116

Dalton´s atomic theory

**4. A chemical reaction involves the rearrangement, separation, or combination of atoms. Atoms are never created or destroyed during a chemical reaction.

3. Atoms of two or more different elements combine to form compounds. A particular compound is always made up of the same kind of atoms and in the same proportions.
4. Atoms of a given element are identical in size, mass, and chemical properties. Atoms of a specific element are different form those of another element
5. All Matter is made up of tiny particles called atoms. Atoms are indivisible and indestructible**

The plum pudding model  J.J. Thompson proposed a model known as the plum pudding model.  Using cathode-ray tubes, Thomson identified the electron.  Consisted of a spherically shaped atom composed of a uniformly distributed positive charge in which the individual negatively charged electrons resided. Atoms are neutral, thus the sphere contains the same quantity of positive and negative charges.