Science 10 - unit A

What are a must in the lab? (4)

• Protective eyewear

• Close-toed shoes

• Clothing cannot be loose

• Hair must be put up

Can you put broken glass into the trash can?

NO! Put broken glass wear and chemical waste into their designated trash bins

What does WHMIS stand for?

Workplace Hazardous Materials Information System

What does MSDS stand for

Materiál Safety Data Sheet

What do material safety data sheets include? (6)

• Melting point

• Boiling point

• Toxicity

• Cleanup procedures

• First aid

• Health effects

Do physical properties change their composition?

No, it still remains chemically the same

What are chemical properties

It's how they react with other substances, and they also change the composition of matter. This is usually irreversible, and they create new materials that have completely new properties from the original substancr

Pure substance

Made up of one kind of particle

Element

Cannot be broken down into any simpler substance

Mixture

Combination of two or more pure substances

Mechanical (heterogenous) mixture

Different substances that make it up are visible

Solution (homogenous) mixture/substance

Different substances are not desperately visible

Suspension

Tiny particles of a substance are held within another

Colloid

A homogenous mixture, but the particles that are suspended are so small that they cannot be easily separated

All chemical reactions are characterized by (2)

• Formation of new substance with new physical and chemical properties

• The release/absorption of energy

Annealing

Heating metal before hammering it into shapes

Smelting

Separating metals from compounds by melting them

John dalton

• Matter consists of individuals atoms

• Billiard ball model

JJ Thompson

• Atoms have electrons

• Plum pudding model

• Ray tube experiment

Ernest Rutherford

• Atoms positive charge was concentrated in a positive nucleus, and atoms are mainly empty space

• Gold foil experiment

• Nuclear model

Niels Bohr

• Nucleus is in the middle and electrons spin around the nucleus in circular orbits (every element emits it's own characteristic emission spectrum)

• Hydrogen emission spectrum

• Planetary model

Metals

They are shiny, metallic lustre, good conductors, malleable ductile, and are solids at room temperature (except for mercury)

Non-metals

They are dull, do not conduct hear or electrical currents, brittle, and can be solid liquid or gas at room temperature

Metalloids

Have characteristics of both metals and non metals, they are often brittle, and although they do conduct electricity, it's not as good as metals

What are each of the rows considered to be

Different valent levels

What do all the elements in the same period have

The same number of rings

What do the elements in the same group have

The same number of electrons in their outer shell

Four important groups

• Alkali metals

• Alkaline earth metals

• Halogens

• Noble gases

What are all atoms made of

• Protons

• Electrons

• Neutrons

Atomic number

Number of protons and electrons in one atom of a specific element

Atomic mass

Total mass of protons and neutrons in one atom of a specific element

Isotopes

Atoms of the same element that contain different numbers of neutrons (we differentiate between isotopes of a given element, we use the mass number)

Atomic mass unit

Atomic mass of an element that is listed on the periodic table

Valence electrons

Electrons in the outer shell that are not full (noble gases have no valence electrons because their outer shell is full)

Ion

An atom or a group of atoms that has a positive or negative electric charge

Cations

Positively charged ions (formed when a metal atom loses valence electrons, and they donate outermost electrons to become more positive)

Anions

Negatively charged ions (formed when a nonmetal accepts electrons into its outermost energy level)

Octet rule

Atoms tend to gain, lose, or share electrons so as to have right electrons in their outer electron shell

Binary ionic compound

Formed between one metal ion and one nonmetal ion (the metal donates and the nonmetal accepts), ionic compounds have a nice fixed ratio

Do ionic compounds form individual molecules

No, they exist as a crystal lattice of alternating positive and negative ions (this produces an electrically neutral compound). There lattices are very stable, so all ionic compounds are solids at room temperature.

Polyatomic ions

Consist of a group of atoms combined together that exist as a single unit with an overall electric charge. Most have a negative charge, and they behave like nonmetals

Molecular compounds

Two or more nonmetal atoms bonded together. Each molecule is independent of the next and is not part of a lattice

Covalent bonds

A strong force of attraction between a metal and a nonmetal atoms. They share their outer electrons.

Electrolyte

Solution that conducts electricity

Solubility

How well a substance dissolves in a solvent (if it dissolves in water it will fork an aqueous solution. If it is not soluble, a solid precipitate is formed)

Examples of a chemical change (5)

• Color change

• Formation of gas

• Formation of precipitate (solid)

• Energy change

• Change in odor