Key Concepts in Chemistry: Atomic Structure, Bonding, and Periodic Table

How has the Dalton model of an atom changed over time?

The Dalton model has evolved due to the discovery of subatomic particles, leading to a more complex understanding of atomic structure.

What is the structure of an atom?

An atom consists of a nucleus containing protons and neutrons, surrounded by electrons in shells.

What are the relative charge and mass of a proton, neutron, and electron?

A proton has a relative charge of +1 and a relative mass of 1, a neutron has a relative charge of 0 and a relative mass of 1, and an electron has a relative charge of -1 and a relative mass of approximately 1/1836.

Why do atoms contain equal numbers of protons and electrons?

Atoms contain equal numbers of protons and electrons to ensure electrical neutrality.

How is the nucleus of an atom described in size?

The nucleus of an atom is very small compared to the overall size of the atom.

Where is most of the mass of an atom concentrated?

Most of the mass of an atom is concentrated in the nucleus.

What is the mass number of an atom?

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

What defines atoms of a given element?

Atoms of a given element have the same number of protons in the nucleus, which is unique to that element.

What are isotopes?

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.

How do you calculate the numbers of protons, neutrons, and electrons in atoms?

To calculate the numbers of protons, neutrons, and electrons, use the atomic number (number of protons) and the mass number (protons + neutrons).

Why are relative atomic masses of some elements not whole numbers?

The existence of isotopes causes relative atomic masses of some elements to be non-whole numbers due to the weighted average of the isotopes' masses.

How did Mendeleev arrange the elements in the periodic table?

Mendeleev arranged the elements by their properties and compounds, organizing them in a periodic table.

How did Mendeleev predict undiscovered elements?

Mendeleev used gaps in his periodic table to predict the existence and properties of elements that had not yet been discovered.

What was Mendeleev's view on the order of elements?

Mendeleev believed he arranged elements in order of increasing relative atomic mass, although this was not always accurate.

What is the atomic number of an element?

The atomic number is the number of protons in the nucleus of an atom and determines the element's position in the periodic table.

How are elements arranged in the periodic table?

Elements are arranged in groups (columns) and periods (rows) based on their atomic structure and properties.

How can you identify metals and non-metals in the periodic table?

Elements can be identified as metals or non-metals based on their position in the periodic table, with metals typically on the left and non-metals on the right.

What are the electronic configurations of the first 20 elements?

The electronic configurations of the first 20 elements can be represented as diagrams or in the form of 2.8.1, etc.

How is electronic configuration related to the periodic table?

the Period Number tells you the number of electron shells, while the Group Number shows the number of electrons in the outer shell, which determines an element's chemical properties

How are ionic bonds formed?

Ionic bonds are formed when electrons are transferred from one atom to another, resulting in the formation of cations and anions.

What is an ion?

An ion is an atom or group of atoms that has a positive or negative charge due to the loss or gain of electrons.

How do you calculate protons, neutrons, and electrons in simple ions?

To calculate protons, neutrons, and electrons in simple ions, use the atomic number and mass number, adjusting for the charge of the ion.

How are ions formed in ionic compounds?

Ions in ionic compounds are formed from their atoms, particularly from elements in groups 1, 2, 6, and 7.

What do the endings -ide and -ate signify in compound names?

The ending -ide is used for simple anions, while -ate indicates a polyatomic ion containing oxygen.

How do you deduce the formulae of ionic compounds?

The formulae of ionic compounds can be deduced from the formulae of the constituent ions, balancing the charges.

What is the structure of an ionic compound?

An ionic compound has a lattice structure held together by strong electrostatic forces between oppositely charged ions.

How is a covalent bond formed?

A covalent bond is formed when a pair of electrons is shared between two atoms.

What results from covalent bonding?

Covalent bonding results in the formation of molecules.

What is the typical size of atoms and small molecules?

Atoms and small molecules are typically on the order of magnitude of picometers to nanometers.

How are simple molecular covalent substances formed?

Simple molecular covalent substances are formed when atoms share electrons, as shown in dot and cross diagrams for compounds like H, HCl, H2O, CH4, O2, and CO2.

How can substances be classified based on bonding?

Substances can be classified as ionic, simple molecular (covalent), giant covalent, or metallic based on their bonding and structure.

How does structure and bonding affect physical properties?

The structure and bonding of substances determine their physical properties, such as melting and boiling points, and conductivity.

What are the properties of ionic compounds?

Ionic compounds typically have high melting and boiling points, strong forces between ions, and conduct electricity when dissolved in water.

What are the properties of typical covalent, simple molecular compounds?

Typical covalent, simple molecular compounds have lower melting and boiling points and do not conduct electricity.

What are graphite and diamond?

Graphite and diamond are different forms of carbon, known as allotropes, and are examples of giant covalent substances.

What are the structures of graphite and diamond?

Graphite has a layered structure with delocalized electrons, while diamond has a tetrahedral structure with strong covalent bonds.

Why do graphite and diamond have different uses?

Graphite's layered structure allows it to be used as a lubricant, while diamond's strong bonds make it suitable for cutting tools.

What are fullerenes and graphene?

Fullerenes, such as C60, and graphene are forms of carbon with unique structures and bonding, leading to distinct properties.

What are simple polymers?

Simple polymers, like poly(ethene), consist of large molecules containing chains of carbon atoms.

What are the properties of metals?

Metals are malleable, ductile, and good conductors of electricity due to the presence of free-moving electrons.

What are the limitations of representations and models in chemistry?

Representations and models, such as dot & cross and ball & stick models, have limitations in accurately depicting the complexities of molecular structures.

What are the properties of most metals?

Most metals are characterized by high melting and boiling points, good electrical and thermal conductivity, and malleability.