THE NATURE OF MATTER (DAY 1) Chapter 2 Lesson 1 Textbook pgs. 34-38 - - PowerPoint PPT Presentation

THE NATURE OF MATTER (DAY 1)

Biology Chapter 2 Lesson 1 Textbook pgs. 34-38

ATOMS

• The atom is the most basic unit of matter.
• Atoms are incredibly small. Placed side by side, 100 million atoms

would make a row about 1 cm long (about width of your little finger).

• Atoms are made of subatomic particles called protons, neutrons,

and electrons.

PROTONS

• Protons are positively charged particles

within the nucleus of an atom.

• The number of protons in the nucleus of

an element is called the atomic number. This is unique for every element.

• Ex: Carbon has an atomic number of 6. This

means EVERY carbon atom in the universe has 6 protons in its nucleus.

• Hydrogen has an atomic number of 1. EVERY

hydrogen atom in the universe has 1 proton in its nucleus.

CARBON

6

C

12.011 HYDROGEN

1

H

1.008

Element Name Atomic Number (aka # of Protons) Atomic Symbol Atomic Mass Element Name Atomic Number (aka # of Protons) Atomic Symbol Atomic Mass

NEUTRONS

• Neutrons are not positively charged or

negatively charged, instead they are neutral particles within the nucleus of an atom.

• The number of neutrons in the nucleus of an

element can be identified by the atomic mass. Subtract the amount of protons from that number and what’s left are the neutrons.

• Ex: Carbon has an atomic mass of 12.011.

Subtract the 6 protons, and you have 6 Neutrons!

• Hydrogen Carbon has an atomic mass of 1.008,

Subtract the 1 proton, and you don’t have any Neutrons! CARBON

6

C

12.011 HYDROGEN

1

H

1.008

Element Name Atomic Number (aka # of Protons) Atomic Symbol Atomic Mass Element Name Atomic Number (aka # of Protons) Atomic Symbol Atomic Mass

ELECTRONS

• Electrons are negatively charged particles that orbit the nucleus of

an atom.

• Electrons are MUCH smaller than Protons.
• They are attracted to the positive charge of the proton and remain

in constant motion in the space surrounding the nucleus.

• Atoms have the same number of protons and electrons. This makes

them electrically neutral

• Electrons are important for the bonding of individual atoms together.

CRASH COURSE CHEMISTRY: THE NUCLEUS

https://www.youtube.com/watch?v=FSyAehMdpyI

ELEMENTS & ISOTOPES

Atoms of an element may have different numbers of neutrons. Ex: All atoms of carbon have 6 protons in the nucleus. Some have 6 neutrons, some have 7, and a few have 8. Atoms of the same element that differ in the number of neutrons they contain are called isotopes. The total number of protons and neutrons in the nucleus is called the mass number. Isotopes are identified by their mass number. Ex: Carbon-12, Carbon-13, and Carbon-14 are all isotopes of the element Carbon. Because they have the same number of electrons, all isotopes of an element have the same chemical properties.

ELEMENTS & ISOTOPES

Ex: Carbon-12, Carbon-13, and Carbon-14 are all isotopes of the element Carbon. C-12 – How many protons? How many neutrons? C-13 – How many protons? How many neutrons? C-14 – How many protons? How many neutrons?

CARBON

6

C

12.011

ELEMENTS & ISOTOPES

Some isotopes are radioactive, meaning that their nuclei are unstable and break down at a constant rate over time. The radiation these isotopes give off can be dangerous, but radioactive isotopes have a number of important scientific uses.

ELEMENTS & ISOTOPES

Some isotopes are radioactive, meaning that their nuclei are unstable and break down at a constant rate over time. The radiation these isotopes give off can be dangerous, but radioactive isotopes have a number of important scientific uses. Geologists can determine the age of rocks and fossils by analyzing the isotopes found in them.

ELEMENTS & ISOTOPES

Some isotopes are radioactive, meaning that their nuclei are unstable and break down at a constant rate over time. The radiation these isotopes give off can be dangerous, but radioactive isotopes have a number of important scientific uses. Radiation from certain isotopes can be used to detect and treat cancer.

ELEMENTS & ISOTOPES

Some isotopes are radioactive, meaning that their nuclei are unstable and break down at a constant rate over time. The radiation these isotopes give off can be dangerous, but radioactive isotopes have a number of important scientific uses. Radioactive isotopes can also be used as “tracers” to follow the movements of substances within organisms.

HOMEWORK: DUE WEDNESDAY 08/31/16

Complete the handout/video questions. Use the periodic table on the back of the handout to complete the front side of the

• worksheet. Each box has ONE trait of certain elements, fill in all necessary

information.

AND NOW TIME FOR AN ACTIVITY!

THE NATURE OF MATTER (DAY 2)

Biology Chapter 2 Lesson 1 Textbook pgs. 34-38

ELEMENTS & THE PERIODIC TABLE

• A chemical element is a pure

substance that consists entirely of

• ne type of atom.
• More than 100 elements are

known, but only about two dozen are commonly found in living

• rganisms.
• Elements are represented by
• ne or two letter symbols. Ex: C,

O, Na, and Ca

CHEMICAL COMPOUNDS

In nature, most elements are found combined with other elements in compounds. A chemical compound is a substance formed by the chemical combination of two or more elements in definite proportions. Chemical formulas are used to represent compounds.

 Ex: Sodium Chloride (table salt) has a formula of NaCl. This shows that there is a 1:1 proportion of sodium to chlorine atoms in each molecule of NaCl.

PHYSICAL & CHEMICAL COMPOUNDS

The physical and chemical properties of a compound are usually very different from those of the elements from which it is formed. Ex: Na is an explosive metal and Cl is a poisonous gas. NaCl is safe to eat! See this really cool chemical reaction:

CHEMICAL COMPOUNDS

Different chemical compounds that contain the same elements may vary in their properties.

 Example: Below are two liquids that look the same, but are very different! Both have hydrogen atoms, both have oxygen atoms. Can you tell a difference?

CHEMICAL COMPOUNDS

Different chemical compounds that contain the same elements may vary in their properties.

 Example: Below are two liquids that look the same, but are very different! Both have hydrogen atoms, both have oxygen atoms. Can you tell a difference?

H2O H2O2

CHEMICAL BONDS: IONIC BONDS

There are 2 main types of bonds that hold compounds together: ionic and covalent.

CHEMICAL BONDS: IONIC BONDS

• An ionic bond is formed when one or more electron is

transferred from one atom to another.

• This normally occurs between a metal and a non-metal.
• An atom that loses an electron becomes positively

charged.

• An atom that gains an electron becomes negatively

charged.

• Charged atoms are called ions.
• These oppositely charged ions have a strong attraction

for one another, forming ionic bonds.

CHEMICAL BONDS: COVALENT BONDS

Sometimes electrons are shared by atoms instead of being transferred. This normally occurs between two non-metals. When electrons are shared, they actually travel around the nuclei of both atoms, forming a covalent bond. When atoms share 2 electrons, it is called a single covalent bond. Sometimes atoms share 4 electrons which is called a double covalent bond. In a few cases, 6 are shared resulting in a triple covalent bond. The structure that results is called a molecule. The molecule is the smallest unit of a compound.

TYPES OF BONDS

THE NATURE OF MATTER (DAY 3)

Biology Chapter 2 Lesson 1 Textbook pgs. 34-38

BOND….NOT JAMES BOND….

To recap from the last 2 days, we discussed two different types of bonds:

IONIC BONDS and COVALENT BONDS Ionic – one atom takes and one atom gives up electrons Covalent – two atoms share electrons EX: NaCl (Ionic) and O2 (Covalent)

VAN DER WAALS FORCES & COVALENT BONDS

Because of their structures, atoms of different elements do not all have the same ability to attract electrons. Some atoms have a stronger attraction for electrons than others. Therefore, when the atoms in a covalent bond share electrons, the sharing is not always equal. This can create regions on the molecule that have a tiny positive or negative charge. When molecules are close together, a slight attraction can develop between oppositely charged regions of nearby molecules. These attractions are called van der Waals forces.

VAN DER WAALS FORCES

GECKOS… THE FORCE IS WITH THEM

GRAB A TEXTBOOK!

• 1. How are gecko feet structured and how has this helped

them adapt to their environment?

• 2. How can studying the structure of gecko feet help

advance science? Please turn to page 38/39 and read about Van Der Waals forces and how the gecko survives in it’s environment. Answer the following questions on a blank piece of paper:

NOW IT’S TIME FOR BIOMIMICRY!

Anyone know what biomimicry is? Biomimicry means “bio” and “imitate” – in other words, to imitate life.

GROUP PROJECT

Take a laminated card and find your table. Read the excerpt and answer the questions associated with the Biomimicry example.