Physical Science Chapter 4 & 5 Flashcards
Valence electrons
The amount of electrons on an elements outer shell
Force of attraction that holds atoms together as a result of the rearrangement of electrons between them
Chemical bonds
Periods
Horizontal Rows on periodic table
An atom or group of atoms that has an electric charge
Ion
How do ions form
When a neutral atom loses a valence electron it loses a negative charge and becomes a positive ion. When a neutral atom gains electrons it gains a negative charge and becomes negative
Atoms that are made of more than one Atom
Polyatomic ions
Attraction between two oppositely charged ions
Ionic bond
Result of ions bonding
Ionic compound
How are the formulas and names of ionic compounds written
First the symbol of positive ion then the negative ion then add subscripts
Tell is the ratio of elements in a compound
Subscripts
What are properties of ionic compounds
Ionic compounds form hard brittle crystals that have high melting points and conduct electric current when dissolved or melted
The ionic compounds that form solids by building up repeating patterns of ions
Crystal
How do ionic compounds(crystals) melt
The ions in the crystal have to melt have to break apart for an ionic compound to melt which is only caused by melting
The chemical bond formed when 2 atoms share electrons
Covalent bond
How are atoms held together in a covalent bond
The attraction between the shared electrons and the protons in the nucleus of each atom hold the atoms together in a covalent bond
A neutral group of atoms joined by covalent bonds
Molecule
Double bond
When two atoms share two pairs of electrons
Triple bond
When two atoms share three electrons
Compound that is made up of molecules
Molecular compound
Properties of molecular compounds
Poor conductivity, low melting point and boiling points
Covalent bond in which electrons are shared equally
Non polar bond
Covalent bond in which electrons are shared unequally
Polar bond
How do you bonded Adams become partially charged
Having an equal sharing of electrons
What is the structure of a metal crystal
Composed of closely packed positively charged metal ions
An attraction between a positive metal ion and the electrons surrounding it
Metallic bond
Properties of metals
Luster malleability ductility thermal conductivity and electrical conductivity
A mixture made of two or more elements with at least one metal
Alloy
How do you know that a chemical reaction has taken place
A new substance is formed
Any change that alters the form or appearance of a substance but does not change it into another substance
Physical change
A change in matter that produces one or more new substances
Chemical change
Substances that undergo a chemical change
Reactant
New substances that form from a chemical change
Products
How do chemical changes occur
One existing bonds break and new bonds form
How do you identify a chemical reaction
Changes in property and changes in energy that you can often observed
How is mass conserved during a chemical reaction
All of the atoms present at the start of the reaction are present at the end
Number placed in front of a chemical formula in an equation
Coefficient
Minimum amount of energy needed to start a chemical reaction
Activation energy
Increases the reaction rate by lowering the activation energy needed
Catalyst
Biological catalyst in body that Help reactions occur at body temperature
Enzymes
Material used to decrease the rate of a chemical reaction
Inhibitor
What affects the rate of a chemical reaction
Surface area temperature concentration and presence of a catalyst and inhibitors
When two or more elements or compounds combined to make a more complex substance
Synthesis reaction
When compounds break down into simpler products
Decomposition reaction
When one element replaces another element in a compound
Replacement reaction
