CHEMISTRY Composition of Matter n Matter Everything in
- Slides: 31
CHEMISTRY
Composition of Matter n Matter - Everything in universe is composed of matter n Matter is anything that occupies space or has mass n Mass – quantity of matter an object has n Weight – pull of gravity on an object
Elements n n Pure substances that cannot be broken down chemically into simpler kinds of matter More than 100 elements (92 naturally occurring)
n n 90% of the mass of a living thing is composed of 4 elements (oxygen, carbon, hydrogen and nitrogen) Each element is represented by a chemical symbol n Consists of 1 -2 letters n First letter is always capitalized
Atoms n The smallest particle of an element Nucleus Neutrons 0 Protons + Electrons -
The Nucleus n n n 2 main regions: Nucleus & electron shell Nucleus consists of positive charged protons and neutral neutrons Nucleus contains most of the mass of the atom
The Protons n All atoms of the same element have the same number of protons Atomic number Atomic symbol Element name Atomic mass
The Neutrons n n The number varies slightly among atoms of the same element Atoms of the same element with different number of neutrons are called Isotopes
Atomic Mass n n The number of protons PLUS neutrons in an atom determines its atomic mass number. The number of electrons is equal to the number of protons in an atom.
The Electrons n n Negatively charged high energy particles with little or no mass Travel at very high speeds at various distances (energy levels) outside of the nucleus
Periodic Table n n n Elements are arranged by their atomic number on the Periodic Table The horizontal rows are called Periods & tell the number of energy levels Vertical groups are called Families & tell the outermost number of electrons
n n n A compound is a pure substance made up of atoms of two or more elements Chemical formula is used to represent a compound. Examples: n H 20, CH 4, CO 2
n n Molecules are the smallest part of a compound. Some molecules are large and complex
Chemical Formulas n n Subscript after a symbol tell the number of atoms of each element H 20 has 2 atoms of hydrogen & 1 atom of oxygen Coefficients before a formula tell the number of molecules 3 O 2 represents 3 molecules of oxygen or (3 x 2) or 6 atoms of oxygen
n The properties of a compound are different from properties of its elements.
n n The outermost electrons in elements determine if they will combine/bond with others. Elements react/bond with other elements to fill their outer energy level – becoming more stable.
n n n Most atoms are not stable in their natural state Tend to react (combine) with other atoms in order to become more stable (undergo chemical reactions) In chemical reactions bonds are broken; atoms rearranged and new chemical bonds are formed that store energy.
Covalent Bonds n Formed when two atoms share one or more pairs of electrons
Ionic Bonds n n n Some atoms become stable by losing or gaining electrons. These atoms are called Ions. Atoms that lose electrons are called positive ions. Atoms that gain electrons are called negative ions.
n Because positive and negative electrical charges attract each other ionic bonds form = attraction between a positive ion and negative ion.
States of Matter n n Atoms are in constant motion The rate at which atoms or molecules in a substance move determines its state.
Solutions
Solutions n A solution is a mixture in which 2 or more substances are uniformly distributed in another substance
n n n Solute is the substance dissolved in the solution n Particles may be ions, atoms, or molecules Solvent is the substance in which the solute is dissolved Water is the universal solvent
n n n Solutions can be composed of varying proportions of a given solute in a given solvent --- vary in concentration (measurement of the amount of solute) A saturated solution is one in which no more solute can be dissolved. Aqueous solution (water as solvent) are universally important to living things
n Dissociation of water n Breaking apart of the water molecule into two ions of opposite charge n H 2 O H+ + OH- is the hydroxide ion H+ is the hydrogen ion
Acids and Bases n n n One of the most important aspects of a living system is the degree of acidity or basicity Acids produce H+ ions Bases produce OH- ions
p. H Scale n n p. H scale measures the concentration of H+ ions and goes from 1 to 14 1 -7 are acids 7 is neutral 8 -14 are bases § Each p. H is 10 X stronger than next § e. g. ph 1 is 10 times stronger than ph 2
Buffers n n Control of p. H is very important Most enzymes function only within a very narrow p. H Control is accomplished with buffers made by the body Buffers keep a neutral p. H (p. H 7)
n n Buffers neutralize small amounts of either an acid or base added to a solution Complex buffering systems maintain the p. H values of your body’s many fluids at normal and safe levels
- Section 1 composition of matter
- Composition of matter section 1
- Composition of matter section 1
- What is everything around us made of
- Percent composition examples
- Composition uniform
- Flowchart of matter
- Study of composition structure and properties
- Section 1 composition of matter
- Homogeneous mixture vs compound
- Flow chart classification of matter
- What is composition in matter
- Section 1 composition of matter answer key
- Classification of matter concept map
- Composition of matter flow chart
- Number of proton
- Properties of solid liquid and gas
- Mixture
- Ib organic chemistry
- Inorganic vs organic chemistry
- Definition of substance
- Chemistry matter and change chapter 7
- Chemistry matter and change chapter 10
- Examples of matter in chemistry
- Chemistry matter and change chapter 7
- Chemistry matter and change chapter 6
- Chemistry matter and change chapter 10 the mole answer key
- Chemistry matter and change answer key chapter 2
- Flowchart undissolved solids
- Matter graphic organizer
- Non examples of homogeneous mixture
- Chapter 4 basic food chemistry the nature of matter