Intro Into Chemistry

Intro to Chemistry

By Hannah Reed

ATOM

THE FUNDAMENTAL CONSTITUTE OF MATTERTHAT RETAINS THE PROPERTIES OF AN ELEMENT

Atoms undergo chemical reactions by gaining or loosing electrons to achieve stability
An atoms properties relate to the number of valence electrons in an atoms outermost shell.
Atoms loose, gain and share electrons to make a variety of chemical bonds which all vary.

The structure of an atom contains electrical charged Protons, Electrons, and Neutrons.

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ANATOMY OF AN ATOM

The nucleus is the centermost part of the atom. This consists of the protons and neutrons.
The electrons stay towards the outermost part of the atom.
These electrons are held in place within ther chells by the attraction to the postive charge of the protons. The further away they are from eachother, the stronger the energy they have.
Each atom will always have the same number of protons. The proton number does not change.
If the number of neutrons within the same element is different that atom is then called an isotope.
The ATOMIC MASS of the cell is always determined by the number of protons and neutrons in the nucleus. that can be determined by adding the number of protons and neutrons together.

Multiple Choice

A Nitrogen atom has 7 protons, 7 neutrons, and 7 electrons. What is the Atomic Mass of the Nitrogen Atom

• 7

• 21

• 14

The number of protons give the ATOMIC NUMBER.
This is different than the Atomic Mass, which is the sum of the protons and neutrons.
The difference between the protons and electrons determine the CHARGE of the atom. an equal number will result in a neutrally charged atom.

• Sodium ion (Na⁺)

• Calcium ion (Ca²⁺)

• Iron(III) ion (Fe³⁺)

• Potassium ion (K⁺)

• Magnesium ion (Mg²⁺)

Positive Atoms

1. Hydrogen (H)

2. Oxygen (O)

3. Carbon (C)

4. Nitrogen (N)

5. Neon (Ne)

Neutral Atoms

Examples:

Negative Atoms

• Chloride ion (Cl⁻)

• Oxide ion (O²⁻)

• Fluoride ion (F⁻)

• Sulfide ion (S²⁻)

• Bromide ion (Br⁻)

ION

An Ion is an atom with either a positive or negative charge.
This happens when an Atom either loses or gains an electron.
This occurs when the number of electrons is either smaller (looses) or greater (gains) than the nucleus.

Multiple Choice

Which of the following, is a Ion

• H

  (Hydrogen)

• O

  (Oxygen)

• Mg2+

  (Magnesium)

• C

  (Carbon)

Multiple Select

Which of the following are Negative Ions

SELECT ALL THAT APPLY

• K+

  (Potassium)

• F-

  (Fluoride)

• Br-

  (Bromide)

• H

  (Hydrogen)

• Cl-

  (Chloride)

​Periodic Table

Starts left to right increasing in Atomic Number.
What is Atomic Number?
To identify the number of protons and electrons, look at the number within the element.
The periodic table lumps elements in vertical groups depending on their properties. The grouping of atoms relate to the number of valence (bonding) electrons that atom has.
The rows are referred to as periods. and they indicate the outermost shell of the atom. these can be further divided into orbitals. these are related to how many electrons can be accommodated at a time.

Chemical Reactions

The valence electrons are the electrons on the outermost shell and they are what is involved in chemical reactions and bonding. The fuller the outer shell, the more stable an atom is, and atoms crave stability. Gases like He (Helium) and Ne (Neon) have full shells and therefore are the most stable and don't react to other elements. These typs of gasses are called Inert Gases.
Other atoms are seeking a full valence shell and therefore loose or gain electrons. This is what forms an Ion.
Gaining electrons is typical in valences greater than 4; which are mostly non metals. and Loosing electrons is typically in valences less than 4; mainly metals.
Atoms that gain electrons then become Negatively charged called Anions
Atoms that loose electrons then become Positively charged called Cations
These exchanges form whats called an Ionic Bond. Compounds within the ionic bonds are soluble on water and conduct electricity. These are Ionic Compounds.
Some atoms like to share electrons to create stability. These are called Covalent Bonds.