Chemistry

What is matter?

Matter is everything that has mass and takes up space, made up of atoms.

What are the two main groups of matter?

The two main groups are pure substances and mixtures.

What are pure substances?

Pure substances are uniform and can be described by an exact chemical formula.

What are elements and compounds?

Elements consist of one type of atom, while compounds are made up of two or more elements chemically bonded.

What are homogeneous mixtures?

Homogeneous mixtures are uniformly mixed and appear as one type of mixture.

What are heterogeneous mixtures?

Heterogeneous mixtures have visible individual parts that make up the mixture.

What is a physical change?

A physical change occurs when a material changes shape or form, with no new materials formed.

What is a chemical change?

A chemical change involves a substance undergoing a chemical process, resulting in a new substance.

What are the signs of a chemical change?

Signs include the appearance of new color, energy release (heat or light), bubbles formation, and precipitate formation.

What is a physical property?

A physical property describes characteristics like color, luster, malleability, and ductility.

What are chemical properties?

Chemical properties describe how a substance reacts with others, such as combustibility and reactivity with water or acid.

What are subatomic particles?

Subatomic particles include protons (positive charge), neutrons (no charge), and electrons (negative charge).

What is the atomic number?

The atomic number is the number of protons (and electrons) in an element.

What is the mass number?

The mass number is the total number of protons and neutrons in an atom.

What does the standard notation indicate?

It shows atomic mass (top left), atomic number (bottom left), and the chemical symbol (middle).

What are the properties of alkali metals?

Alkali metals are soft, shiny, silver, and very reactive.

What distinguishes alkaline earth metals?

Alkaline earth metals are shiny, silver, and reactive but not as much as alkali metals.

What are noble gases?

Noble gases are very unreactive and do not react with other elements.

What characterizes halogens?

Halogens are very reactive non-metal gases that can produce poisonous fumes.

What is the Bohr-Rutherford diagram?

It illustrates the arrangement of electrons around the nucleus, with specific shells holding certain numbers of electrons.

What is a Lewis dot diagram?

A Lewis dot diagram shows the arrangement of electrons in shells around the nucleus.

What are valence electrons?

Valence electrons are the electrons in the outermost shell of an atom.

What is the octet rule?

The octet rule states that atoms strive to have eight electrons in their outer shell.

What are ions?

Ions are charged atoms based on the difference between the number of protons and electrons.

What is ionic bonding?

Ionic bonding occurs between a metal and a nonmetal where electrons are transferred.

What is covalent bonding?

Covalent (molecular) bonding occurs between nonmetals where electrons are shared.

How do you name ionic compounds?

Ionic compounds are named without prefixes, using Roman numerals for transition metals and ending with -ide.

How do you name covalent compounds?

Covalent compounds use prefixes (mono, di, tri) to indicate the number of atoms and end with -ide.

What is the law of conservation of mass?

The law of conservation of mass states that matter cannot be created or destroyed.

What are the parts of a chemical equation?

A chemical equation includes symbols representing atoms, subscripts for the number of atoms, and coefficients for the number of molecules.

What is the synthesis reaction type?

A synthesis reaction is represented as A + B → AB.

What is a decomposition reaction?

A decomposition reaction is represented as AB → A + B.

What is a single displacement reaction?

A single displacement reaction is represented as AB + C → AC + B.

What is a double displacement reaction?

A double displacement reaction is represented as AB + CD → AC + DB.

What happens during combustion?

In complete combustion, hydrocarbons react with oxygen to produce water, carbon dioxide, and energy; incomplete combustion produces carbon monoxide.

What is the definition of matter?

Matter is anything that has mass and takes up space.

What distinguishes pure substances from mixtures?

Pure substances have a uniform composition and specific chemical formulas, while mixtures contain two or more pure substances combined.

What is the distinction between elements and compounds?

Elements consist of only one type of atom, whereas compounds are made up of two or more different types of atoms chemically bonded together.

How can you identify a homogeneous mixture?

A homogeneous mixture appears uniform throughout and does not display visible individual components.

What is a characteristic of a heterogeneous mixture?

A heterogeneous mixture has distinct parts or phases that can be visually identified.

What occurs during a physical change?

A physical change alters the form or appearance of a substance without changing its chemical composition.

What are common indicators of a chemical change?

Indicators include a change in color, the release of energy (heat/light), formation of gas bubbles, and the creation of a precipitate.

What is the importance of observing physical and chemical properties?

Observing these properties helps in identifying and characterizing substances, as well as predicting their behaviors during reactions.

Why are protons and neutrons located in the nucleus?

Protons and neutrons are located in the nucleus because they contribute to the atom's mass and stability, while electrons orbit around the nucleus.

How is atomic mass calculated?

Atomic mass is calculated as the sum of an atom's protons and neutrons.

What does the periodic table reveal about elements?

The periodic table organizes elements by increasing atomic number and groups them based on similar chemical properties.

What is the significance of valence electrons in bonding?

Valence electrons determine how an atom bonds with others, as they are involved in chemical reactions and formation of compounds.

What do shared electrons in covalent bonding indicate?

Shared electrons in covalent bonding signify that atoms are sharing their valence electrons to achieve a full outer shell.

How does one determine the molecular formula of a compound?

The molecular formula of a compound is determined by the types and numbers of atoms present, often using subscripts in formulas.

What role do coefficients play in chemical equations?

Coefficients indicate the number of molecules or moles of a substance involved in a reaction and help balance chemical equations.

What effects do combustion reactions have?

Combustion reactions can produce energy and various products, including carbon dioxide and water, which are important for energy production and environmental considerations.