Unit 2 Chemistry Study Guide (Doyle)

What are the six parts to Dalton's Atomic Theory?

1) Matter is composed of extremely small particles called atoms 2) Atoms are indivisible and indestructible 3) Atoms of a given element are identical in size, mass, and chemical properties 4) Atoms of a specific element are different from those of another element 5) Different atoms combine in a simple whole number ratio to form compounds 6) In a chemical reaction, atoms are separated, combined, or rearranged

What is an extensive property?

A property dependent on the amount of substance present.

Describe the model of this atom. Where is the positive charge? Negative charge?

All the positive charge, and most of an atom's mass, is located in what he called the nucleus.

The smallest particle of an element that retains the properties of the element is called a(n) _________________.

Atom

The Greek Philosopher Democritus was the first to suggest that matter was not infinitely divisible. He called the indivisible particles____________________.

Atomos

The nucleus occupies a small space but contains almost all the mass of an atom. It is very ___________

Dense

Scientists that discovered charged particles smaller than an atom were originally working with devices called___________.

Cathode rays.

Define physical change.

Change that alters a substance without changing its composition (ex. crumpling foil, cutting paper, breaking a crystal)

Greeks believed that matter was composed of which four elements?

Earth, water, fire, and air

True or False? We can actually see atoms with microscopes.

FALSE

Liquid

Form of matter that flows, has constant volume, takes shape of container

Gas

Form of matter that only flows to conform to the shape of its container, fills entire volume of the container

Which form of matter can be easily compressed?

Gas

___________ was the first scientist to suggest that the charged particles were smaller than an hydrogen atom- the smallest atom

JJ Thompson

Which scientists helped discover neutrons in 1932?

James Chadwick

______________________ is anything that takes up space and has a mass.

Matter

Robert Milikan determined the charge and mass of an electron using which experiment?

Oil Drop Experiment?

The first model of an atom was proposed by J.J Thomson and was called the ____________ model.

Plum Pudding

Define chemical change. Give example

Process that involves one or more substances changing into new substances. (ex. mixing chemicals)

Which scientist helped to disprove this early model of an atom with his gold foil experiment?

Rutherford

Define chemical properties

The ability or inability of a substance to combine with or change into one or more other substances. Ex. copper oxidizing

Solid

a form of matter that has its own shape and volume

How did scientists know the cathode ray consisted of negatively charged particles?

a) Because the cathode ray is deflected in a magnetic field, the particles in the ray must be charged b) Because the cathode ray tub is deflected toward the positively charged plate by an electric field, the particles in the ray must have a negative charge.

What is an intensive property?

independent of the amount of substance present

Define physical properties. Give three examples of physical properties?

physical and chemical. Examples of physical property= color, volume, density

Proton

positively charged particle

Neutral atoms have equal numbers of

protons and electrons

In a chemical reaction, the starting substances are called ___________ and the resulting substances are called _____________.

reactants, products