Matter and Energy
! Matter—anything that occupies space and has mass (weight)
! Matter may exist as one of three states:
o Solid: definite shape and volume
o Liquid: definite volume; shape of container
o Gaseous: neither a definite shape nor volume
Matter and Energy
! Matter may be changed
o Physically
! Changes do not alter the basic nature of a substance
o Chemically
! Changes alter the chemical composition of a substance
Matter and Energy
! Energy—the ability to do work.
o Has no mass and does not take up space
o Kinetic energy: energy is doing work
o Potential energy: energy is inactive or stored
Matter and Energy
! Forms of energy
o Chemical energy is stored in chemical bonds of substances
o Electrical energy results from movement of charged particles
o Mechanical energy is energy directly involved in moving matter
o Radiant energy travels in waves
Matter and Energy
! Energy form conversions
o ATP (adenosine triphosphate) traps the chemical energy of food in its
bonds
Composition of Matter
! Elements—fundamental units of matter
o 96 percent of the body is made from four elements:
1. Oxygen (O)
2. Carbon (C)
3. Hydrogen (H)
4. Nitrogen (N)
© 2015 Pearson Education, Inc.
, ! Periodic table contains a complete listing of elements
Composition of Matter
! Atoms
o Building blocks of elements
o Atoms of elements differ from one another
o Atomic symbol is chemical shorthand for each element
o Indivisible (“incapable of being divided”)
Subatomic Particles
! Nucleus
o Protons (p+) are positively charged
o Neutrons (n0) are uncharged or neutral
! Orbiting the nucleus
o Electrons (e–) are negatively charged
Subatomic Particles
! Atoms are electrically neutral
o Number of protons equals numbers of electrons in an atom
o Positive and negative charges cancel each other out
! Ions are atoms that have lost or gained electrons
Subatomic Particles
! Planetary model
o Portrays the atom as a miniature solar system
o Protons and neutrons are in the nucleus
o Electrons are in orbitals
Subatomic Particles
! Orbital model
o More modern
o Predicts chemical behavior of atoms
o Electrons are depicted by an electron cloud, a haze of negative charge,
outside the nucleus
Subatomic Particles
! Electrons determine an atom’s chemical behavior
! Although outdated, the planetary model is simple and easy to understand and use
© 2015 Pearson Education, Inc.
! Matter—anything that occupies space and has mass (weight)
! Matter may exist as one of three states:
o Solid: definite shape and volume
o Liquid: definite volume; shape of container
o Gaseous: neither a definite shape nor volume
Matter and Energy
! Matter may be changed
o Physically
! Changes do not alter the basic nature of a substance
o Chemically
! Changes alter the chemical composition of a substance
Matter and Energy
! Energy—the ability to do work.
o Has no mass and does not take up space
o Kinetic energy: energy is doing work
o Potential energy: energy is inactive or stored
Matter and Energy
! Forms of energy
o Chemical energy is stored in chemical bonds of substances
o Electrical energy results from movement of charged particles
o Mechanical energy is energy directly involved in moving matter
o Radiant energy travels in waves
Matter and Energy
! Energy form conversions
o ATP (adenosine triphosphate) traps the chemical energy of food in its
bonds
Composition of Matter
! Elements—fundamental units of matter
o 96 percent of the body is made from four elements:
1. Oxygen (O)
2. Carbon (C)
3. Hydrogen (H)
4. Nitrogen (N)
© 2015 Pearson Education, Inc.
, ! Periodic table contains a complete listing of elements
Composition of Matter
! Atoms
o Building blocks of elements
o Atoms of elements differ from one another
o Atomic symbol is chemical shorthand for each element
o Indivisible (“incapable of being divided”)
Subatomic Particles
! Nucleus
o Protons (p+) are positively charged
o Neutrons (n0) are uncharged or neutral
! Orbiting the nucleus
o Electrons (e–) are negatively charged
Subatomic Particles
! Atoms are electrically neutral
o Number of protons equals numbers of electrons in an atom
o Positive and negative charges cancel each other out
! Ions are atoms that have lost or gained electrons
Subatomic Particles
! Planetary model
o Portrays the atom as a miniature solar system
o Protons and neutrons are in the nucleus
o Electrons are in orbitals
Subatomic Particles
! Orbital model
o More modern
o Predicts chemical behavior of atoms
o Electrons are depicted by an electron cloud, a haze of negative charge,
outside the nucleus
Subatomic Particles
! Electrons determine an atom’s chemical behavior
! Although outdated, the planetary model is simple and easy to understand and use
© 2015 Pearson Education, Inc.
