Chemistry Chemical Interactions Ch. 1

Bell Work 11/17/09 What is matter? What are the three states of matter? What is an atom?

Matter – is anything that has mass and takes up space. MATTER is never created or destroyed, it only changes form.

Atoms – The basic building blocks of all the substances in the universe. All things are made up of atoms. http://science.howstuffworks.com/nanotechnology1.htm

Elements – Are made of one kind. of atom grouped Elements – Are made of one kind of atom grouped together and cannot be broken down into simpler substances. Identical atoms make up elements 110 elements make up all the known substances on earth!!!

Atoms contain one or more PROTONS, NEUTRONS, and ELECTRONS

Electrons Protons and neutrons make up the nucleus of an atom. Electrons “float” around the nucleus of an atom. nucleus Electrons

Protons – Particles that have a positive electric charge. Neutrons – have no electric charge. Electrons – Particles with a negative charge located outside of the nucleus.

The nucleus of the atom is. positively charged (+). The The nucleus of the atom is positively charged (+). The negatively (-) charged electrons surround the nucleus to balance the charge of the atom to neutral. The number of protons equals the number of electrons.

Atomic number – the number of protons in an atom Atomic number – the number of protons in an atom. Found above the element symbol. Mass number – is equal to the number of protons plus the number of neutrons. The number of neutrons is determined by subtracting the atomic number from the mass number.

Bell Work 11/18/10 Make the following chart on your paper and fill it in Atomic Number Atomic Mass # of Protons # of Neutrons Calcium - Ca Barium - Ba Selenium - Se Gold - Au Lithium - Li

Bell Work 11/22/10 Make the following chart on your paper and fill it in Protons Atomic Mass Neutrons Electrons Ti Be Kr

Special atoms The number of protons always stays the same, however sometimes the number of neutrons or electrons changes. Electrically Stable – atoms that have no electric charge

Special Atoms Isotopes – atoms of the same element that have different numbers of neutrons.

Special Atoms Ions – formed when an atom loses or gains one or more electrons Lose 1 electron becomes + ion Gain 1 electron becomes - ion

Bell Work 11/23/10 Determine the name of each isotope Protons = 6 2. Protons = 20 Neutrons = 7 Neutrons = 22 Determine the name of each ion 3. Protons = 7 4. Protons = 5 Electrons = 9 Electrons = 3

Bell Work 11/24/10 Determine if each is an ion, isotope, or electrically stable and name the element Protons = 11 3. Protons = 18 Neutrons = 11 Neutrons = 22 Electrons = 11 Electrons = 20 2. Protons = 10 4. Protons = 21 Neutrons = 10 Neutrons = 20 Electrons = 9 Electrons = 21

The number in the right corner of each element represents the amount of protons that element has……thus the amount of electrons.

Groups – are the numbers at the top of the periodic table that represent the number of electrons in the outermost shell (energy level). Periods – the number to the left of the periodic table that represents the number of shells an element will have.

Period number Group number

Bell Work 11/29/10 Draw each of the following elements. Be sure to put the correct number of protons and neutrons in the nucleus. Oxygen Silicon Lithium

Electrons circle around the nucleus in shells or energy levels. As an element loses an electron it loses energy and as an element gains electrons it gains energy. Each circle or shell is limited to how many electrons it can hold.

Valence electrons – electrons in the outermost energy level of an atom. The valence shell can have 1 to 8 electrons in it depending on its place on the periodic table. Elements to the left have 1 and elements to the right have 8.

Electrons in valance shells that are not full will either gain electrons or lose electrons to become full

Bell Work 11/30/10 List the number of valence electrons in each element, then state how many electrons it will gain or lose in order to be full and name the ion. Sodium Calcium Fluorine Sulfur

Metals – elements that conduct electricity, heat well, and have a shiny appearance Reactive metals- metals in group 1-2 of the periodic table, these metals are very reactive Transition metals – metals in groups 3-12. Generally less reactive than other metals.

Nonmetals – an element that is not a metal and has properties generally opposite of a metal. Halogens – elements in group 17. Very reactive nonmetals that easily form compounds called salts with many metals. Noble gases – elements in group 18. Almost never react with other elements. Metalloids- elements that have properties of both metals and nonmetals.

Bell Work 11/25/09 List the number of valance electrons for each of the following elements. Ne Mg P C Draw each of the following elements 5. Fluorine 6. Aluminum

Bell Work 12/1/09 List the number of protons, electrons, and neutrons for the isotopes and ions. Na – 25 F – 21 Cl-1 Ca+2 List the number of valance electrons for each of the following elements and name the ion that will make it “happy and full”. 5. Beryllium – Be 6. Sulfur – S 7. Draw the following: Boron and Sulfur

Radioactive Decay Radioactive atoms produce energy and particles from their nuclei. The identity of these atoms changes because the number of protons changes. Occurs at a steady rate that is characteristic of the particular isotope Half-life – the amount of time it takes for one-half of the atoms in a particular sample to decay