Chapter 2/3 - Molecules Flashcards
Any substance in the universe that has mass and occupies space
Matter
Small particles that make up matter
Atoms
Tunneling microscopy
Technology used to locate atoms
What located at the center of an atom?
Nucleus
What subatomic particles form the nucleus?
Protons and neutrons
What subatomic particles surround an atom?
Electrons
Electrons are found in
Orbitals
Orbitals surround the
Nucleus of an atom
Region within an atom where the electron will most likely be located
Orbital
How many electrons can an orbital contain
2
Atomic theory
- Every atom contains electrons
2. Protons and neutrons are at the core of an atom
What charge does a proton have?
Positive
What charge does an electron have?
Negative
What charge does a neutron have?
No charge
Any substance that cannot be broken down into any other substances by ordinary chemical means
Element
Atomic number is equal to the number of
Protons
True or False
Atoms with the same atomic number belong to the same element
True
True or False
Different atoms have the same number of protons
False
Different atoms have a different number of protons
Pure substance that contains one atom
Element
True or false
Our body is made up of elements
True
Oxygen has eight protons so that atomic mass is
8
The atomic mass is equal to
Protons plus neutrons
Which subatomic particles contribute to mass
Protons and neutrons
True or false
Electrons contribute to mass and are heavier than protons and neutrons
False
Electrons do not contribute to mass and are not heavier than protons or neutrons
An atom is generally neutrally charged when
Where is an equal number of protons and electrons
Keeps electrons in their orbitals but opposite charge attraction
Protons
Can be gained or lost, turning into an ion
Electrons
Ion
When the number of electrons does not equal the number of protons
Name two types of ions
Cation
Anion
Cation
- Positive charge ion
2. Contains more protons than electrons
Anion
- Negative charge ion
2. Less protons than electrons
True or false
Typically, an atom has one electron for each proton and is thus electrically neutral
True
The chemical behavior of an atom is due to the number and configuration of
Electrons
Positive charges in the nucleus of an atoms are neutralized by
Negatively charged electrons
Isotope
Different form of the same element that possesses the same number of protons but different number of neutrons
The mass of atoms and subatomic particles is measured in units called
Daltons
A proton weighs approximately
1.007 Dalton
A neutron weighs approximately
1.009 dalton
Electrons weigh
1/1840 of a dalton, so they contribute almost nothing to the overall mass of an atom
Na , Cl
Na+ —> Cl-
Which element is a cation/ which is an anion? Explain.
Na+ is the cation. It shared/lost its electron to Cl-. Giving it more protons than electrons. Thus, the positive charge.
Cl- is the anion. A gain an electron from an Na+. Giving it more electrons than protons. Thus, the negative charge.
Hydrogen has 1 proton, 0 neutrons.
Deuterium has 1 proton, 2 neutrons.
Tritium has 1 proton, 3 neutrons.
What is being described?
An isotope.
Same element possessing the same number of protons but different number of neutrons.
Radioactive isotope
- Unstable isotopes that will break down into an atom with a lower number of neutrons and or atomic number
- Undergoes radioactive decay
- release energy
Radioactive decay
Unstable isotope that decays to an element with a lower atomic number
True or False
Some radioactive isotopes are more unstable than others
True
The decay time for a radioactive isotope is expressed as
Half life
The time it takes for 1/2 of the atom in a sample to decay
Half life
100%. Vs. 50% Ex: 12C --- > Half Life = 7C
How are fossils dated?
Through radioactive decay
Emits large quantities of energy that are harmful to living cells
Radioactive decay
Determines the chemical behavior of an atom
Electrons
What shapes are ORBITALS known to have
Spherical
Dumbbell shaped
Describe the 1s orbital
- Closest to the nucleus of an atom
2. Lowest energy level
Describe 2s, 2p orbital
- Further away from the nucleus of an atom
- Second lowest energy level
- 2s = 2 electrons
- 2p = 3 orbitals
**Max of eight electrons
Name all energy levels alphabetically from lowest to highest
- K —-> lowest (1s)
- L (2s;2p)
- M
- N —-> highest
How can you move electrons away from the nucleus?
Add energy
How can you move electrons closer to the nucleus?
Release energy
When energy is released electrons move
Closer to the nucleus —–> because energy at lower orbitals contain less energy than orbitals further away from the nucleus
When energy is absorbed electrons move
Further away from the nucleus, or the outer orbital
What energy level is closest to the nucleus and which is furthest?
Close , K
Far , N
- How many electrons can the outer most energy level contain?
- Name two exceptions.
- 8
- He, H —-> Each contains a 1s orbital ONLY.
How can you increase the potential energy of an electron
Input energy
The amount of energy and electron possesses it is related to its distance from
The nucleus
Electrons that are the same distance from the nucleus have the same
Energy
Oxidation
Transfer/Loss of an electron by an atom or molecule, in metabolism
Usually associated with the gain of oxygen or loss of hydrogen
Reduction
Gain of electron
Redox Reaction
An atom or molecule becomes oxidized, while another is reduced in the same reaction
How many naturally occurring elements are there?
90
Each w different number of protons and a different arrangement of electrons
True or false
Elements have a repeating pattern of 6 elements
False
Elements have a repeating pattern of eight elements
Electrons in the outer most energy level are called
Valance electrons
Nonreactive/ Inert / “Happy”
Elements that contain all eight valance electrons in their outer most energy level
If an element contains all eight electrons in its outer most energy level can it bond with other elements
No because it is non-reactive, happy or inert
Elements that contain less than eight electrons are
Very reactive
Elements that contain seven electrons will try to
Fill up their outer most energy level
Elements that contain one electron will try to
Rid there outermost electron
What is it called when one element loses its electron to another element
Ionic bond
Octet rule
Atoms like to completely fill their outer energy levels
If helium has two valance electrons and nitrogen has four valance electrons, which element would be very reactive?
Helium is non-reactive due to its 1s orbital, therefore nitrogen would be very reactive
What 12 elements are found in living organisms?
C, H, O, N, P, S, Na, K, Ca, Mg, Fe, Cl
Which elements make up 96.3% of your bodyweight?
C, H, O, N
Compounds found in living organisms that contain carbon
Organic compounds
Carbon is found in
Sugars, fatty acids, and amino acids