Finals 8 Flashcards
What is matter?
Anything that has mass and takes up space
What is a physical property?
A characteristic of a pure substance that can be observed without changing it into another substance
What are 3 examples of the physical properties of matter?
Density, melting point, texture and color
What is a chemical property?
A characteristic of a pure substance that describes its ability to change into different substances
What are 3 examples of the chemical properties of matter?
Flammability, new substances being formed, ability to react
Difference between a chemical change and a physical change?
A physical change alters the form of a substance but does not change it into a new substance. Whereas a chemical change alters the form but changed it into a new substance.
3 types of matter?
Mixture, element, and conpound
What is a mixture?
Two or more substances that are mixed togther, but not chemically combined
What is an element?
A pure substance that cannot be broken down into any other substance by chemical or physical means
What is a compound?
A pure substance made of two or more substances chemically combined in a set ratio
Pure substances include:
Elements and compounds
What are atoms?
The basic, smalest particle from which all atoms are found
What happens to the energy within the matter that is changing?
The energy is either increasing or decreasing
In order for a change of state to occur:
Thermal energy is either added or taken away
The atomic # tells you the number of
Protons and electrons
The atomic mass tells you the:
The sum of the atomic # and the neutrons
Families are the _______ columns and periods are the _________ columns
Vertical, horizontal
Why do families have similar characteristics?
They group how they react to form compounds
What do valence electrons determine?
Many properties of that element, including the ways in which the atom can bond with other atoms
List 3 traits of metals and non-metals each:
Metals: shiny, good conductors, high melting point
Non-metals: dull, bad-conductors, low melting point
What is special about Alkali Metals?
Most reactive metals
What is unique about semi-metals?
They are non reactive
What are the noble gases and what makes them special?
Family 18A, they tend to be unreactive.
During chemical reactions, which part of the atom is involved in bonding?
Valence electrons
During a chemical reaction, electrons are either
Given, taken, or shared
What tells you the number if valence electrons in an atom?
Family #
Difference between covalent and an ionic bond?
A covalent bond is a chemical bond formed when two atoms share electrons, an ionic bond is the attraction between two oppositely charged ions
How many valence electrons do most atoms want to be stable?
8
In an ionic bond, positive ions always bond with
Negative ions
What type of bond is formed when atoms share valence electrons?
Covalent bond
5 signs of a chemical change:
Changes in properties, color change, precipitate forming, texture, hardness
Chemical reactions occur when bonds are either
Broken or formed
When chemical reactions, atoms are not created or destroyed, they are just
Rearranged
What does a chemical formula show?
The substances involved in a reaction
What does a chemical equation show?
Elements in a compound
Exothermic ___energy, endothermic _____ energy
Releases(heats up), absorbs (cool down)
Amount of energy required to start a reaction
Activation energy
Rates of chemical reactions can be affected by these four things
Surface area, temperature, concentration, and the presence of catalysts and inhibitors
4 pure forms of carbon
Diamond, graphite, fullerene, nanotube
What is a carbohydrate and what 3 elements are in them?
Energy-rich organic compound made of the elements carbon, hydrogen, and oxygen
What is a double bond?
A chemical bond formed when atoms share two pairs of electrons
What is a triple bond?
A chemical bond formed when atoms share three pairs of electrons
What is a polymer?
A large molecule in which many smaller molecules are bonded together
5 examples of polymers?
Proteins, amino acids, plastics, composite, cellulose
How many bonds can a carbon atom make?
4
Carbon can form:
ringed chains, branched chains, and straight chains
What are some characteristics of acids?
Sour, reacts with metals and carbons
What are some characteristics of bases?
Tastes bitter, slippery, turns red litmus paper blue
Type of ions produced by acids and bases?
Acids: hydrogen ion
Bases: hydroxide ion
The scale that measures the amount of hydrogen in a solution is called the
pH scale
A neutral solution has a pH of
7
The stronger the acid, the ____ the pH, the stronger the base the ____ the pH
lower, higher
What does a neutralization reaction produce?
Salt
