ACS - Big Ideas - Second Edition

ACCM

Atoms have unique chemical identities based on what?

Number of protons in the nucleus

What plays the key role for atoms to bond with other atoms

Electrons

Atoms display what in their structures?

Periodicity and observable phenomena that depend on that structure

Most information about atoms is inferred from from studies on collections often involving

an interaction with electromagnetic radiation

Macroscopic samples of matter or measured in

moles

Atoms maintain their identity except in

nuclear reactions

When do ions arise?

When the number of electrons and protons are not equal, and can be formed from atoms

Because protons and electrons are charged, physical models of bonding are based on

Electrostatic forces

Because chemical bonds arise from sharing of negatively charged valence electrons between positively charged nuclei, the overall electrostatic is

attractive

When chemical bonds form, how is energy released?

Overall energy of the bonding atoms is lowered relative to free atoms

To break a chemical bond requires an

input of energy

Bonding is

utilizies the construction o fmolecular orbitals for the bond based on overlap of atomic orbitals on the constituent atoms

Covalent bonds are categorized based on the number of electrons (pairs) shared

Most common are single, double, and triple bonds

Metallic bonding arises in many solids and fundamentally involves

sharing of valence electrons among many positively charged “cores” over extended distances

Atoms combine to form new properties based on what?

Structural and electronic features

Models exist that allow the prediction of the shape of chemicals about any bonding atom in a what?

Molecule

What plays an important role in how atoms interact within molecules and molecules are observed in many experiements

Symmetry

What structure will give rise to to chirality, which can play an important role in observed chemical and physical properties

Three-dimensional

Reactions of molecules can often be understood in terms of subsets of atoms called?

Functional groups

What trends among elements can be used to organize the understanding of structure and function for related chemical compounds

Periodic

What plays an important role in understanding the properties of these systems?

Solid state, extended systems and geometric structutres

Intermolecular forces are what?

Generally weaker, on a n individual basis, than chemical bonds, but the presence of many such interactions may lead to overall strong interactions

For large molecules, intermolecular forces may occur between?

Different regions of the molecule. In these cases, they are sometimes termed noncovalent bonds

Intermolecular forces can be categorized based on

Permanence and structural details of the dipoles involved

For condensed phases that are not structures of extended chemical bonds, the physical properties of the state are

strongly influenced by the nature of the intermolecular forces

The energy consequences of chemical reactions that take place in condensed phases usually must include

intermolecular forces