chemistry

What is the definition of Matter?

Anything that has mass and takes up space (volume).

What are the three subatomic particles, their charges, and their locations?

Protons (positive, in nucleus), Neutrons (neutral, in nucleus), and Electrons (negative, in shells surrounding nucleus).

How do you determine the number of Protons in an atom?

It is equal to the Atomic Number.

How do you calculate the number of Neutrons?

Atomic Mass (rounded) minus the Atomic Number.

What is the "Billiard Ball" model and who created it?

John Dalton; he proposed atoms are solid, indivisible spheres.

What did J.J. Thomson discover with his "Plum Pudding" model?

He discovered the electron and suggested they were embedded in a positive sphere.

What was the result of Rutherford’s Gold Foil experiment?

He discovered the nucleus (a dense, positive center) and realized atoms are mostly empty space.

What is the Bohr-Rutherford model?

A model where electrons travel in specific orbits (shells) around a central nucleus.

What are the electron capacities for the first four shells?

1st: 2, 2nd: 8, 3rd: 8, 4th: 18.

What is Standard Atomic Notation?

A way to write an element where the Mass Number is on the top left and the Atomic Number is on the bottom left of the symbol.

What is the difference between a Physical Property and a Chemical Property?

Physical properties are observed without changing the substance (color, density); chemical properties describe how it reacts to form something new (flammability, reactivity with acid).

Define Malleability and Ductility.

Malleability: ability to be hammered into sheets. Ductility: ability to be stretched into wires.

What are the three main categories of elements on the Periodic Table?

Metals (left), Non-metals (right), and Metalloids (along the staircase).

What are the characteristics of Alkali Metals (Group 1)?

They are very soft, silver-grey, and highly reactive because they have 1 valence electron.

What are the characteristics of Halogens (Group 17)?

They are highly reactive non-metals with 7 valence electrons.

Why are Noble Gases (Group 18) stable and unreactive?

They have a full valence shell (Stable Octet).

What is a Cation?

A positively charged ion formed when a metal loses electrons.

What is an Anion?

A negatively charged ion formed when a non-metal gains electrons.

What is the difference between an Ionic Bond and a Covalent Bond?

Ionic involves the transfer of electrons from a metal to a non-metal; Covalent involves non-metals sharing electrons.

What are the 7 Diatomic Molecules (HOFBrINCl)?

Hydrogen, Oxygen, Fluorine, Bromine, Iodine, Nitrogen, Chlorine.

What is a Homogeneous mixture vs. a Heterogeneous mixture?

Homogeneous (Solution) looks like one substance; Heterogeneous (Mechanical) shows visible different parts.

What are three indicators of a Chemical Change?

1. Gas production (bubbles), 2. Unexpected color change, 3. Energy release (heat/light).

In the formula 2H2O, what do the 2s represent?

The big "2" is the coefficient (2 molecules); the small "2" is the subscript (2 atoms of Hydrogen per molecule).

How many total atoms are in Pb(NO3)2?

9 atoms total (1 Lead + 2 Nitrogen + 6 Oxygen).

What is an Isotope?

Atoms of the same element with the same number of protons but different numbers of neutrons (different mass).

What is the "Octet Rule"?

Atoms tend to gain, lose, or share electrons to achieve a full outer shell of 8 electrons.

Who created the first periodic table, and arranged elements by increasing atomic mass?

Mendele

Whats the characteristics or description of a substance?

A property

What determines the property of a substance?

The electrons

What are families?

Columns on the periodic table that have similar properties

Whats a period?

A horizontal row of elements in the periodic table

Describe Alkali metals

1st column, and has 1 valence electron, highly reactive

Describe Alkaline Earth metal

2nd group and has 2 valence electrons

Name the characteristics of Metals

Shiny, conducts electricity, malleable, ductile, solids (except mercury)

Describe the properties of metalloids

Solids, some lustre, behave like non-metals, have some ability to conduct electricity

What are valence electrons?

Electrons on the outermost

Characteristics of Non-metal

Mostly gas but exists in solds, poor conductors, no lustre, no ductile, insulators

Name two ways atoms can bond

-Sharing electrons
-Giving up or gaining electrons

Who defined an element as a pure substance that can not be chemically broken down further?

Antoine de Lav