Atoms, Ions, and Molecules Flashcards

Questions and Answers

What are chemical elements?

Substances composed of only one type of atom (correct)

Atoms that form ionic bonds

Mixtures of different atoms

Atoms with a net positive charge

Where are electrons located?

Orbitals

What does an atomic number represent?

The number of protons that the atom has, it identifies the element

What is the mass number?

The number of protons and neutrons an atom has Signup and view all the answers

What is the net electrical charge of every atom in the universe?

Electrically neutral Signup and view all the answers

What is a valence electron shell?

The outermost electron shell Signup and view all the answers

What is an electron shell?

The energy level occupied by electrons that represents the amount of potential energy stored within the electrons Signup and view all the answers

Why does it matter whether an atom has an open or closed valence shell?

Atoms with closed valence shells are the most stable and least reactive with other atoms, those with open shells are looking for ways to close theirs. Signup and view all the answers

For the first three electron shells, how many electrons are needed to produce a closed shell?

1st = 2 and 2nd = 8 and 3rd = 8 Signup and view all the answers

By what means can an atom achieve a closed valence shell?

An atom may give, take, or share electrons with another atom to achieve a full valence shell Signup and view all the answers

What is an ion?

An atom or chemical group that does not have equal numbers of protons and electrons Signup and view all the answers

What is a cation?

Positive ions formed by losing electrons Signup and view all the answers

What is an anion?

Negative ions formed by gaining electrons Signup and view all the answers

How do ions form and how do they differ from atoms?

Ions form by donating or accepting electrons so that they do not have the same numbers of protons and electrons, unlike atoms Signup and view all the answers

What is an ionic bond?

An ionic bond is the attraction between oppositely charged ions Signup and view all the answers

What is bicarbonate's chemical formula?

HCO3- Signup and view all the answers

What is the chemical symbol for Calcium?

Ca2+ Signup and view all the answers

What is the chemical symbol for Chloride?

Cl- Signup and view all the answers

What is the chemical formula for Hydrogen (free proton)?

H+ Signup and view all the answers

What is the chemical formula for Hydroxide?

OH- Signup and view all the answers

What is the chemical symbol for Magnesium?

Mg2+ Signup and view all the answers

What is the chemical formula for Phosphate?

PO4^3- Signup and view all the answers

What is the chemical symbol for Potassium?

K+ Signup and view all the answers

What is the chemical symbol for Sodium?

Na+ Signup and view all the answers

What is an electrolyte?

A substance that disassociates in water to form ions Signup and view all the answers

What is the Octet Rule?

With the exception of the innermost shell, atoms are most stable energetically when they have 8 electrons in their valence shell. Signup and view all the answers

What happens the closer an atom is to closure?

The more reactive and aggressive it will be Signup and view all the answers

What happens the further the electron shell is from the nucleus?

The more potential energy that will be stored within the atoms Signup and view all the answers

Study Notes

Chemical Elements

Composed solely of one type of atom.
Fundamental building blocks of matter.

Electrons

Located in orbitals surrounding the nucleus of an atom.
Each electron shell represents a specific energy level and potential energy storage.

Atomic Number

Represents the number of protons in an atom, which identifies the chemical element.

Mass Number

Defined as the total count of protons and neutrons in an atom's nucleus.

Electrical Charge

All atoms in the universe are electrically neutral, meaning protons and electrons are in equal numbers.

Valence Electron Shell

The outermost electron shell that determines an atom's reactivity.

Electron Shells

Energy levels filled by electrons, with specific capacities:
- 1st shell: 2 electrons
- 2nd shell: 8 electrons
- 3rd shell: 8 electrons

Stability of Valence Shells

Closed valence shells indicate stability and low reactivity.
Atoms with open valence shells seek to complete them by gaining, losing, or sharing electrons.

Ions

Formed when an atom or chemical group has unequal quantities of protons and electrons.
Cations are positively charged, formed by losing electrons.
Anions are negatively charged, resulting from gaining electrons.

Ionic Bonds

Attractions occur between oppositely charged ions, forming ionic compounds.

Common Ions and Their Charges

Bicarbonate (HCO₃⁻)
Calcium (Ca²⁺)
Chloride (Cl⁻)
Hydrogen (H⁺, free proton)
Hydroxide (OH⁻)
Magnesium (Mg²⁺)
Phosphate (PO₄³⁻)
Potassium (K⁺)
Sodium (Na⁺)

Electrolytes

Substances that dissociate in water to form ions, essential for various biological functions.

Octet Rule

Atoms are most stable when they have eight electrons in their valence shell (with the exception of the innermost shell).
Indicates that atoms will not readily donate or accept electrons when stable.

Reactivity of Atoms

Atoms closer to having a full valence shell are more reactive, aggressively seeking to achieve stability.
The potential energy within an atom increases with the distance of the electron shell from the nucleus.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the foundational concepts of chemistry with these flashcards focused on atoms, ions, and molecules. Each card provides a definition or question related to essential chemical terminology and principles. Perfect for students looking to enhance their understanding of chemistry basics.