Matter and Energy #1

1. States/ Properties/Changes2. Forms & Transfer of Energy

Matter

• Anything that HAS MASS and they OCCUPY SPACE.

• Ex? – List 5.

Section 1

Kinetic Theory

• Describes the behavior of matter • All matter is made of atoms and molecules

that act like tiny particles.• These tiny particles are always in motion.

The higher the temperature, the faster the particles move.

• At the same temperature, the massive (heavier) particles move slower than the less massive (lighter) particles.

4 States of Matter

• There are 4 states of matter the kinetic theory helps describe: solids, liquids, gases and plasma. These states of matter are physically different.

Solid

• Molecules do not move freely, they vibrate in place, giving solids a rigid structure.

• They have ordered, fixed, and tightly packed arrangements due to chemical bonding and intramolecular interactions

LEAST AMOUNT OF ENERGY

Liquids

• Molecules are closer together and moves faster than solids.

• Molecules are weakly attracted to one another moving less freely than gas. They move randomly and fill the container in which they are held.

• The rate at which a liquid moves/flows is known as its viscosity. The slower moving= more viscous. Ex: Glass.

Gases • molecules are in constant, random

motion spreading out in all directions (diffusion).

• They exert pressure. The pressure is made by individual gas molecules hitting the sides of the container.

• As the temperature rises, the molecules begin to move faster = the pressure increases

• (the molecules hit the sides more often and with greater energy/force= increased pressure).

http://titanium.fullerton.edu/shock/PHASED.htm

Plasma

• Usually an ionized gas.

• Does not definite shape.

• Conducts electricity well.

• Effected by electric and magnetic fields.

MOST AMOUNT OF ENERGY

• http://www.harcourtschool.com/activity/states_of_matter/

Changes in State

• Energy’s Role: required to move or change matter. Energy is transferred in all changes of state. • ENERGY REQUIRED- to melt or

evaporate any substance.• Sublimation- physical change of a

solid to gas- energy is required.

Changes in State cont.• Energy Released- during condensation.

Gas → Liquid or Liquid → solid.• Changes of state:

• solid → liquid → gas, does not change the composition or the mass.

Laws of Conservation

• Law of Conservation of Matter: Matter cannot be created or destroyed.

• Law of Conservation of Energy: Energy cannot be created or destroyed. (This is the 1st law of thermodynamics!)

Properties of Matter• Chemical Properties: how a substance

reacts with other substances, chemically, to form new *** composition will be changed***substances.

• Reactivity- the ability of a substance to react chemically with another substance. How much it will react depends on what they are reacting with and in what kind of environment the rxn is occurring.

• Ex: rust (the ability of iron to react with oxygen), and combustion/flammability. Electronegativity, ionization potential, pH , heat of combustion, toxicity, stability, flammability…

Properties of Matter cont.• Physical Properties: characteristics of the

substance which can be measured/observed without changing the composition of the substance.

• Melting point- temp. @ which a solid becomes a liquid.

• Boiling point- temp. @ which a liquid becomes a gas.

• Density- the mass per unit volume.• Buoyancy- the force with which a more dense

fluid pushes a less dense substance upward.* These properties help determine the use of the

compound. *

Prop. Of Matter cont.• Chemical Changes:

occurs when a substance changes composition to form a new substance.

• Na2O + H2O→ 2NaOH

• Combustion: CH4 + 2O2→ CO2 + 2H2O

Prop. Of Matter cont.• Physical Changes: only the physical

properties/form change. The substance may look different but the atoms of the substance are not changed.

• Ex: changes of state- solid to liquid to gas. The substance looks different but the composition remains the same (H2O is still H2O).

• Grinding peanuts to make peanut butter.

• Pounding a gold nugget to make a ring** The melting point, density or color of gold doesn’t change**

Prop. Of Matter cont.

• Melting, freezing and evaporation are physical changes. So is dissolving…

• Ex: sugar water. The Sugar molecules are not changed… they only spread out in the water. Proof? The water still tastes sweet; thus, dissolving is a physical change.

Energy (heat) TransferA Review

• Radiation- energy transfer through empty space.• No direct contact is required to transfer

heat.

• Conduction- heat transfer by DIRECT CONTACT

• Convection- Heat transfer by the movement of a heated fluid.

Energy (heat) TransferA Review

• Energy (heat) always transfers

from HIGH to LOW. NEVERNEVER from low to high.

Conductors vs. Insulators

• Conductor- matter which allow current/heat to flow.

• Currents flow via ELECTRONS jumping from one atom to the next.

http://www.ndt-ed.org/EducationResources/HighSchool/Electricity/conductorsinsulators.htm

Conductor

Insulator

• Insulator- matter which resists the flow of current/ heat.

CALCULATING DENSITY• Which box would weigh more? Why?

• The box that has more red balls (more mass per unit of volume). • This property of matter is called density. • Density is expressed in g/cm3.

CALCULATING DENSITY• The formula for calculating density is:

• Solve: A piece of tin has a mass of 16.25g and a volume of 2.26 cm3. What is the density of the tin?

• A man has a 50.0 cm3 bottle completely filled with 163g of a slimy green liquid. What is the density of the liquid?

• A piece of metal has a density of 11.3 g/cm3 and a volume of 6.7cm3. What is the mass of the metal?