Chapter 2: Energy and Matter

Measuring Energy calorie – the amount of heat required to raise the temperature of 1 gram of water 1 degree C. 4.184J = 1cal Calorie (food) = 1000 calories

The point at which the motion of particles ceases K = 273 + C Measuring energy Kelvin – based on absolute zero The point at which the motion of particles ceases K = 273 + C C = K - 273

Matter Matter – anything that has mass and volume Solid – definite mass and volume Liquid – definite volume, no definite shape Gas – no definite shape or volume

Ex. Density, color, mp, bp, crystalline shape and conductivity Properties of Matter Physical Properties – Can be observed without changing the identity. Ex. Density, color, mp, bp, crystalline shape and conductivity

Ex. Flammability, ability to rust Properties of Matter Chemical Properties – Have to change the substance to observe Ex. Flammability, ability to rust

Ex. Breaking glass, melting butter Changes Physical Change – does not alter the substance Ex. Breaking glass, melting butter Chemical Change – Changes that alter the substance. Baking a cake, iron rusting

Law of Conservation of Matter Matter cannot be created nor destroyed, it just changes form. Ex. K + C  KC If I have 2.4g of K and 3.6g of C how many g of KC would I have? 6.0g

Energy Energy is the capacity to do work Potential Energy- stored energy Kinetic Energy – energy of motion

Elements, compounds, mixtures Element – a substance that cannot be separated into simpler substances by chemical means. Found on the periodic table. Compound – substance that contains 2 or more elements, chemically combined in fixed proportions.

Elements, compounds, mixtures Mixture- Blend of 2 or more pure substances Substances retain their own properties Separated by physical means Filtration, distillation

solutions Homogeneous solutions – no visibly different parts Ex. Salt water, air Heterogeneous Mixture – Visibly different parts Chocolate chip cookies