Chapter 1B Notes -Physical and chemical changes are usually accompanied by energy changes energy- the capacity to do work work- action of a force (push or pull) through a distance kinetic energy (KE)- energy of motion potential energy (PE)- energy of position -potential energy is converted to kinetic energy when a force acts on an object total energy = KE + PE

thermal energy- energy associated with the temp of an object ex- weight held up high (PE), then dropped (KE), then hits the ground (thermal energy) -KE is transferred into the ground increasing the temp of the ground a slight amount Law of Conservation of Energy- energy is neither created nor destroyed -back to example- PE becomes KE which becomes thermal energy and is released -when potential energy is high, object is less stable

Types of Measurement 1) Qualitative -gives descriptive non-numeric results ex- feeling someone’s head for a fever *may be different from person to person 2)Quantitative -gives definite numeric results ex- using thermometer to check for fever

International System of Units (SI) – system of measurement based on the metric system used by scientists globally Measurement Length- size, distance -basic unit is the meter (m) 1 meter = inches -Find your height in meters!!!

Mass- the amount of matter in an object -basic unit is the kilogram (kg) 1 kg = 2.2 lbs -Find your weight in kilograms!! weight- measure of the pull of gravity on a given mass -mass is always the same, but weight can change -weight on the moon is 1/6 your weight on the Earth -Find your weight on the moon!!

Volume- the amount of space an object occupies -basic unit is the Liter (L) 1 L = 1.06 quarts -anything cubed is also a volume **1 milliliter = 1 cm 3 HOW?? (length)(width)(height/thickness) = volume (cm)(cm)(cm) = cm 3 (cc) = mL Time -basic unit is the second (s) -most familiar unit of measurement

Temperature- how hot or cold something is, average kinetic energy -basic unit is kelvin (K) -avoids negative numbers by assigning coldest temperature possible (-273°C or 459°F) at 0K, absolute zero 273 K = 0°C K  °C = K - 273°C  K = °C Celsius (°C) is mostly used by scientists

°F  °C = (°F -32)ºC  ºF = (1.8)(ºC) Convert normal body temp of 98.6°F to °C and Kelvin!! (98.6°F = 37°C = 310K) Common Conversions 1km = 0.62 mi1m = in 1in = 2.54 cm1kg = 2.2 lbs 1lb = g1oz = 28.35g 1L= 1.06 qt1 gal = 3.79 L

Metric System -based on scales/multiples of 10 -uses prefixes to convert numbers **Table** Practice 980 fg = ? ng1000 mm = ? µm 20 EL = ? GL ag = ? pg dm = ? km1.2 hL = ? nL cg = ? Dg3 00 Mm = ? Tm L = ? PL4300 nm = ? mm

Density- ratio of the mass of a substance to its volume *page 20 Table 1.4 Density = mass/volumed = m/V density = g/cm 3 or g/mL mass = (density)(volume)m = dV volume = mass/densityV = m/d Page 20- Example 1.3

intensive property- property that is independent of the amount of substance ex- density extensive property- property that depends on the amount of a substance ex- mass Scientific Notation -used to make large numbers look smaller and small numbers look larger

Significant Figures -in science, measurements are reported so that every digit is certain except for the last one Rules for Counting Sig Figs 1)all non zero digits are significant 2)all zeroes between two #’s are significant 3)all zeroes to the right of a # without a decimal point are NOT significant 4)all zeroes to the right of a # with a decimal point are significant

5) all zeroes to the left of a number containing a decimal point are NOT significant 6)if counting, all numbers are significant Examples 1100m ML2003g (2) (3) (4) 3000 cars (4) (3) (4)

Atlantic Rule -if a decimal point is absent, start counting from the first non-zero digit from the Atlantic Ocean side inland (right  left) Pacific Rule -if a decimal point is present, start counting from the first non-zero digit from the Pacific Ocean side inland (left  right) **All #’s significant when counting 10400L308g m L 230L g 5600mg200 pens

Multiplying/Dividing Sig Figs -the answer must have the same number of sig figs as the factor with the fewest sig figs Ex- (40)(56)(340) (1 sig fig) Ex ÷ (3 sig figs)

Adding/Subtracting Sig Figs -the result must have the same number of decimal places as the quantity with the fewest decimal places Ex (2 decimal places) Ex- 5.9 – (1 decimal place)

Problems With Multiple Operations Ex – (1 sig fig) Try pg. 26 Ex 1.6 and pg. 27 Practice 1.6

Precision- how close a series of measurements are to one another Accuracy- how close measured values are to the actual value *Can be precise, but not accurate or vice versa