Chapter Two: Chemistry Flashcards
Matter
Anything that occupies space and has mass
States of Matter
Solid, Liquid, or Gas
Energy
The capacity to do work or put matter into motion
Two types of energy
Kinetic and Potential
What is an atomic symbol
One of two letter chemical shorthand for each element
What is the atomic number?
- Element’s defining trait
- Tells the number of protons and electrons
Top number above the atomic symbol
Where is the atomic mass found?
Bottom number
What is the formula to find number of neutrons?
Atomic mass - atomic number = neutrons
What charge are protons?
Positive
What charge are electrons?
Negative
What is the formula to find number of nucleons?
Protons + Neutons
What is the backbone of biological macromolecules?
Carbon
What are physical elements?
Detectable with our senses
What are chemical elements?
How atoms interact and bond with one another
What 4 elements make up 96.1% of the body’s mass?
Hydrogen
Oxygen
Carbon
Nitrogen
Which 9 elements make up 3.9% of body mass
Calcium
Phosphorus
Potassium
Sulfur
Chlorine
Magnesium
Iodine
Iron
What are trace elements?
Very minute mounts of 11 elements that make up less than 0.01% of the body’s mass
Chemical energy
Stored in bonds of chemical substances
Electrical energy
Results from movement of charged particles
Mechanical energy
Directly involved in moving matter
Atoms
- Smallest stable unit of matter
- Unique building blocks for each element
- Give each element its physical & chemical properties
- Smallest particles of an element with properties of that element
Atoms are composed of __ particles
subatomic particles
Protons, neutrons, and electrons
Protons, neutrons, and electrons are
Subatomic particles
Where are protons located?
In the nucleus
Where are neutrons located?
In the nucleus
Where are electrons located?
In orbit in an electron cloud
What is the charge and mass of protons?
- positive charge
- Mass = 1 amu
What is the charge and weight of a neutron?
- no charge
- Mass = 1 atomic mass unit (amu)
What is the charge and weight of an electron?
- Negative charge
- o amu
Number of __tons and __trons are always equal
Number of protons and electrons are always equal
Atomic number
- Number of protons in nucleus of the atom
Written as subscript to left of atomic symbol
Mass number
- Total number of protons and neutrons in nucleus of the atom
- Total mass of atom
- Written as superscript to left of atomic symbol
What are Isotopes?
- Structural variations of atoms
- Differ in the number of neutrons they contain
Atomic weight
Average of mass numbers (relative weights) of all isotopes of an atom
Radioisotopes
- Heavy isotopes decompose to more stable forms
- Similar to tiny explosion
- Can transform into different element
__ are energy relationships between electrons of reacting atoms
Chemical bonds
Electrons can occupy up to __ electron shells (energy levels) around nucleus
7
Valence shell
- outermost electron shell
- Electrons here have most potential energy and are chemically reactive electrons
Octet rule
Except for the first shell (full with two electrons) atoms interact to have eight electrons in their valence shell
Rule of 8’s
Chemically Inert Elements
- Stable and unreactive
- Valence shell fully occupied or contains eight electrons
- Noble gases
Chemically reactive elements
- Valence shell is not full
- Tend to gain, lose, or share electrons to achieve stability
Three major types of chemical bonds
Ionic
Covalent
Hydrogen
Ions
Atom gains or loses electrons and becomes charged
When the number of Protons ≠ Number of Electrons
Anion
Atom that gained one or more electrons
Atom that gained one or more electrons
Anion
Cation
Atom that lost one or more electrons
Atom that lost one or more electrons
Cation
Attraction of opposite charges results in an __ bond
ionic
Covalent bonds
- Formed by sharing of two or more valence shell electrons
- Allows each atom to fill its valence shell at least part of the time
Nonpolar covalent bonds
- Electrons shared equally
- Produces electrically balanced, nonpolar molecules such as CO2
Small atoms with six or seven valence shell electrons are __
electronegative
Most atoms with one or two valence shell electrons are __
electropositive
Ionic bond
Complete transfer of electrons
Polar covalent bond
Unequal sharing
of electrons
Nonpolar covalent bond
Equal sharing of
electrons
Molecule
- Two or more atoms bonded together
Compound
Two or more different kinds of atoms bonded together
(Can only be seperated by breaking bonds)
All are homogeneous
Mixture
Two or more components physically intermixed
(No chemical bonding between components - Can be separated by physical means, such as straining or filtering)
Heterogeneous and homogeneous
Three types of mixtures
- Solutions
- Colloids
- Suspensions
Homogeneous mixtures
Solutions
Heterogeneous mixtures
Colloids
Suspensions
Solvent
- Substance present in great amount in a mixture
- usually water
Solute
smaller amounts in a mixture, dissolved in a solvent
Colloids
Emulsions
- large solute particples do not settle out
ex: jello
Suspensions
Large visible solutes settle out
EX: blood
Chemical reactions occur when
chemical bonds are formed, rearranged, or broken
Patterns of chemical reactions
- synthesis
- decomposition
- exchange
reactants
The number and kinds of the interacting substances
products
The chemical composition of the result of the reaction
The number and kinds of the interacting substances
Reactants
The chemical composition of the result of the reaction
Products