2Matter Anything that has mass and takes up space. 3 types of matter: a). Solidb). Liquidc). Gas
3SolidsAny substance that has a definite shape and definite volume.
4LIQUIDAny substance that has a definite volume but not a definite shape. It takes the shape of its container.
5GasAny substance that has no definite shape or definite volume.
6Physical ChangeChanging the physical properties of a substance without changing the substance itself.
7Physical PropertiesThe characteristics of a substance that you can observe with the senses.They include:shapecolorvolumetextureodor
8ATOMSThe smallest particle of matter that can exist and still have the properties of a particular kind of matter.
91. Nucleus – central part of the atom Atoms are composed of:1. Nucleus – central part of the atom2. Protons – positively charged particles (+)3. Neutrons – uncharged particles4. Electrons – negatively charged particles (-)electronsprotonsneutronsorbit
10Orbits (Energy Levels) A region around the nucleus in specific energy levels.There are 7 energy levels known to date.1st energy level holds a maximum of 2 electrons.2nd energy level holds a maximum of 8 electrons.3rd energy level holds a maximum of 18 electrons.
11ElementsSubstances that are made up entirely of atoms of the same kind and cannot be divided into simpler substances by ordinary chemical means.
13Symbol – a shorthand method of representing an element. Atomic Number - # of protons in the nucleus of the element.Atomic Mass Number - # protons + # of neutrons# protons = # of electrons; atoms are electrically neutral
14How many protons, electrons, and neutrons are found in the following atoms? Calcium –protons –electrons –neutrons -Iodine –protons –electrons –neutrons -I5374Ca20Gold –protons –electrons –neutrons -Au79118
15Molecule – the smallest part of a substance that has all the chemical properties of that substance. Made up of atoms of the same or different kinds of atoms. Compound – matter made up of 2 or more atoms that are chemically combined from different elements.H2O NH3 O2 2NaCl 4H2 CO2 He
16Chemical (Molecular) Formulas Shows the kind and number of atoms in a molecule or compound.Ex: H2 - hydrogen gasH – symbol2 – subscript2 atoms of Hydrogen2H2O C6H12O6
17Chemical Change Always uses or gives off energy Results in a new substanceEx: H O 2H2ONa Cl NaCl
18Mixtures – substances that are combined but not changed chemically Mixtures – substances that are combined but not changed chemically. Ex: cereal & milk vegetable salad How could a mixture of salt and water be separated? 2 types: a) homogeneous – one in which the substances are evenly distributed. b) heterogeneous – the substances are not evenly distributed.
19MixturesSolution – a mixture that is formed when the molecules of one substance mix evenly with those of another substance.ex: Kool-Aid lemonadeSuspension – a heterogeneous mixture containing particles distributed with a liquid, gas, or solid.ex: soil & water RBC & bloodColloid – a mixture composed of particles dispersed in a mediumex: gelatin (partly solid & partly liquid)How is fog a colloid?
20Acids & BasesAcid – a chemical that produces hydrogen ions in a water solution.Ex: HCl H2SO4Base – a chemical that produces hydroxide ions in a water solution.Ex: NaOH
21pHpH scale – scale for measuring how acidic or basic various solutions are.Ranges from 0 to 14a solution w/a pH of 7 is neutrala solution w/a pH below 7 (0 to 6.9) is acidica solution w/a pH above 7 (7.1 to 14) is basicEx: stomach acidvinegarmilkbloodsoap136.57.310