Chemistry - Menihek Jr High Science€¦ · Project Introduction Due at the end of Chemistry unit ... – Elephant toothpaste:

CHEMISTRYObjectives 1-9

Matter

■ anything that has mass and

takes up space (volume).

■ It can be in the form of a solid,

liquid or gas (States of Matter)

■ Determine Particle Arrangement of solids, liquids, and gases

from the video.

■ Bill Nye: Phases of Matter

Particle Arrangement

Solid Liquid Gas

Matter is made of Atoms

■ When all atoms that make up a

substance are the same, then that

substance is an element.

■ Elements are made of only one kind of

atom. Because of this, elements are

called "pure" substances.

■ An atom is the smallest piece of an

element that still has the properties of

that element.

All the atoms within this substance

are sodium atoms

Sodium

Element

Sodium Element

Matter is made up of Elements.

■ Elements are substances that

contain one type of matter and

cannot be broken down or

separated into simpler

substances.

Example

The element aluminum is a lightweight, shiny

metal. If we took a piece of aluminum and cut

it into small pieces, it would still be aluminum.

Activity

Refer to the periodic table and locate the elements;

■ Aluminum

■ Tungsten

■ Gold

■ Titanium

■ Americium

■ Lead

Record the elements symbol

Record a fundamental use of each element (Text Pg 21)

Describing Matter

■ https://www.youtube.com/watch?v=8ta4HygRCpk

Describing Matter

#1. Physical Properties (Text Page 18)

■ Characteristics of matter that are often observed or measured.

■ Can be either qualitative (observed) or quantitative (measured).

Physical Properties of MatterQualitative Quantitative

State Solubility

Color Conductivity

Malleability Viscosity

Ductility Density

Texture Melting point

Magnetism Boiling point

lustre

Physical Properties & Physical Change

■ Characteristics that don’t

change the substance

■ no new substance formed

■ Ex: sugar dissolving in water

#2. Chemical Properties (Text Page19)

■ Observed when substances react with each other.

■ Determines a substances usefulness.

Chemical Properties of Matter

■ Reactivity

■ Combustibility

■ Toxicity

Chemical Properties & Chemical Change

■ Characteristics that change

the substance

■ A new substance is formed

Ex: Burning paper

■ Atoms of different elements can

combine to make new

substances.

■ If atoms combine that are of two

or more different elements, we

call that a compound.

Example

Iron oxygen Iron oxide

“Rust”

Assignment

■ Properties of Matter (Physical or Chemical Property)

Physical & Chemical Property Computer Lab

■ http://www.glencoe.com/sites/common_assets/science/virt

ual_labs/BL01/BL01.swf

Physical & Chemical Property Lab

Theory vs Law

■ A theory is less well supported

than a law.

■ Most laws are supported by

different and robust

experimental evidence.

Science Laws

■ Descriptions of events, patterns, or relationships that have

been observed over and over again.

■ Laws do not provide explanations, they simply state what

happens

Science Theories

■ Explanations of observations supported by evidence.

■ Theories may change as new facts become available. Laws

are constant.

Atomic Theory

■ The descriptions of matter and how it behaves.

■ Has undergone many modifications as new facts became available.

■ https://www.youtube.com/watch?v=thnDxFdkzZs

Early ideas... 2000 years ago

Empedocles:

■ matter was composed of four

“elements”; earth, air, water,

and fire.

Democritus

■ eventually a substance will be

cut into a piece that can no

longer be cut. He called this

piece atomos.

Development of Atomic Theory

■ John Dalton (1766-1844)

■ He suggested that the particles

that make up matter are like

small, hard spheres that are

different for different elements.

■ He defined an atom as the

smallest particle of an element.

Dalton’s Model... Billiard Ball Model

He believed atoms were small, hard spheres

like a billiard ball! (draw the ball)

J.J. Thomson (1856-1940)

■ He suggested that all atoms must contain electrons(negative charge).

■ His model pictured a positively charged ball with the negatively charged electrons embedded in it.

Thomson’s Model... Raisin Bun Model

Ernest Rutherford (1871-1937)

■ He discovered that atoms have a nucleus.

■ two kinds of particles in the nucleus;

1. protons (positive charge)

2. neutrons (neutral)

Rutherford’s Model... Planetary Model

Niels Bohr (1885-1962)

■ He proposed that electrons

surround the nucleus in

specific energy levels or shells.

■ Each electron has a particular

amount of energy.

Bohr’s Model... Orbital Model

■ Rutherford was able to develop Thomson’s model due to the development of new technologies. (gold foil experiment)

■ The development of cyclotrons and proton accelerators have further developed the model accepted today.

Billiard’s Ball Plum Pudding Planetary Orbital

Inside the Atom

Board Work

■ Atom Components (subatomic particles)

Atomic Number = • the number of protons in the nucleus.

It also represents the mass of the

protons. (amu)

• It also equals The number of electrons

surrounding the nucleus.

• All atoms are neutral in charge, so the

# of positive charges (protons) = the #

of negative charges (electrons)

Atomic Mass• The average mass of the atoms of an

element.

• Mass is the number of protons and

neutrons in an atom.

• # of neutrons = Mass number – atomic #

• Example: 7 – 3 = 4 neutrons.

Worksheet

■ Requires booklet and textbook page 50.

■ Review subatomic particles on the periodic table

■ Worksheet - Interpreting Atomic Theorists Models

Project Introduction

■ Due at the end of Chemistry unit (booklet 3)

■ Start researching ideas to complete a home experiment. (Video Project)

■ MythBusters: S13E05 - Do Try This At Home (FULL EPISODE) - YouTube

■ SciGuys:

– Elephant toothpaste: https://www.youtube.com/watch?v=-RRTnIGr6fg

– Rock Candy https://www.youtube.com/watch?v=VpOU0Fo7QfU

– Burning steel wool https://www.youtube.com/watch?v=nWdK1L7GXys

■

■ Ms. Dawe will go into more detail with you!