Biology - Characteristics of Life and Water
Which kinds of atoms tend to interact with others? Why?
Atoms whose outer shells are not full. Since their outer shells are incomplete, all of these atoms react readily with other atoms.
Relative mass
Average of the protons and neutrons found in the nucleus
How are elements located on the periodic table?
Based on atomic structure
Metal + non-metal =
ionic compound
Isotopes
Atoms of the same element that have different numbers of neutrons
polar covalent bond
A covalent bond in which electrons are not shared equally. The pulling of shared, negatively charged electrons closer to the more electronegative atom makes that atom partially negative and the other partially positive.
Cell
A fundamental unit of life
How many degrees can a snowy owl rotate its head?
270 degrees
How many periods are on the periodic table?
7
How many properties do we associate with life?
7
How many groups are there in the periodic table?
8 main groups, 18 total
Covalent bond
A chemical bond that involves sharing a pair of electrons between atoms in a molecule. When two atoms with incomplete outer shells react, each atom will share, donate, or receive electrons. That way both partners end up with completed outer shells.
Molecule
A cluster of small chemical units called atoms held together by chemical bonds
Organelle
A membrane-enclosed structure that performs a specific function within a cell
Diatomic molecule
A molecule consisting of two atoms
Anion
A negatively charged ion
Cation
A positively charged ion
Example of evolutionary adaptation
A snowy owl's sharp talons facilitate prey captured and its feathered feet keep it warm in its cold habitat.
Symbol
Abbreviation for a chemical element
Response to the environment
All organisms respond to environmental stimuli
Population
All the individuals of a particular species living in an area.
Ion
An atom or group of atoms that has a positive or negative charge resulting from the gain or loss of one or more electrons.
Electronegativity
An atom's attraction for shared electrons
Organism
An individual living thing
Tissue
An integrated group of cells with a common function, structure, or both.
Go from biosphere to molecule
Biosphere (whole world) --> Ecosystem (Florida Everglades) --> Community (all organisms in the wetland ecosystem) --> Population (all alligators living in the wetland) --> organism (an American alligator) --> organ system (nervous system) --> Organ (brain) --> Tissue (nervous tissue) --> cell (nerve cell) --> organelle (nucleus) --> molecule (DNA)
Chemical reaction
Breaking existing chemical bonds and forming new ones.
How can life be defined?
By a set of common properties.
Example of energy processing
Caterpillars will use the chemical energy stored in plants to power its own activities and chemical reactions
Example of order in life
Cells create order
Groups
Columns
Names of the electron shells
Go from nucleus out; k (1), l (2), m (3)
Ecosystem
Consists of all the organisms living in a particular area, as well as the physical components with which all the organisms interact, such as air, soil, water, and sunlight.
Important exception in the octect ruel
Hydrogen only needs two valence electrons
Valence
Electrons on the outermost energy level of an atom
Methods of separating mixtures:
Evaporation, gravity, screens, filters, other means
Evolutionary adaptation
Evolve over many generations, as individuals with traits best suited to their environments have greater reproductive success and pass their traits to offspring.
When water is in a liquid form:
There are a few bonds
Ionic bond
Forms when atoms are held together by the attraction of opposite charges
Types of mixtures:
homogeneous and heterogeneous
Poor metals
Good conductors, but not as good as others
Alkali Metals
Group 1, 1 electron in outer level, very reactive, Hydrogen is in this group.
Halogens
Group 17, 7 valence electrons (want one more), not very stable
alkaline earth metals
Group 2, 2 electrons in the outer level, reactive metals, fairly stable
Transition metals
Groups 3-12, varied numbers of electrons, different characteristics
What makes water cohesive?
Hydrogen bonding
4 main types of bonds
Ionic bonds, covalent bonds, hydrogen bonds, Van Der Waals Interactions
What size particles do heterogeneous mixtures have?
Large particles
Order
Living cells make up complex organizations.
Organ
Made up of several tissues, each in turn make up a group of similar cells that preform a specific action.
Regulation
Many types of mechanisms regulate an organisms internal environment, keeping it within limits that sustain life.
Electrons
Negative charge (unless it is an ion)
Neutrons
No charge (neutral)
What parts of the atom are involved in its chemical activity?
Only the electrons
Properties we associate with life
Order, reproduction, growth and development, energy processing, regulation, response to the environment, evolutionary adaptation
Reproduction
Organisms reproduce their own kind. The creation of individuals from existing ones.
Only other elements that Hydrogen bonds to:
Oxygen, Nitrogen, and Fluorine
When water is in a vapor form (steam):
There are no bonds
What causes water molecules to combine?
Positive and negative ends of the polar molecule attract causing them to combine.
Protons
Positive charge
Which two subatomic particles are located in the nucleus of an atom?
Protons and neutrons
Atomic number equals the number of _____ or ______.
Protons; electrons
Atomic mass equals the numbers of ______ + ________.
Protons; neutrons
What can weak bonds be used for?
Reversible interactions
How to find the number of neutrons
Round the relative mass - the atomic number
Periods
Rows
What do elements in the same period have in common?
Same number of atomic orbitals
What do elements from the same family have in common?
Similar properties, same number of valence electrons (except for elements in the transition metal family)
What size particles do homogeneous mixtures have?
Smaller particles
Suspensions
Solid particles in gas or liquid that settle out due to gravity (example: sand and water)
Organ system
Such as the circulatory system or nervous system, consists of several organs that cooperate in a specific function.
Octet rule
Tendency of atoms to prefer eight electrons in their outer shells
What happens the farther you go down the period table?
The elements get more radioactive.
Community
The entire array of organisms in an ecosystem.
Chemical bonds
The interaction between atoms that bond
How did snowy owls adapt to the sub-zero weather in their environment?
Their white color helps them adapt to the snow, and they are able to adapt for protection.
Example of organ systems
The organs of the nervous system are the the brain, the spinal cords, and the nerves.
Biology
The study of life
Energy processing
The use of chemical energy to power an organism's activities and chemical reactions
When water is in a solid form (ice):
They are many bonds
What have the eye-lids of the snowy owls helped them adapt to?
They are nocturnal but have to hunt during the day in the summer. Their eye-lids protect them from the sun.
Why can owls turn their heads so much?
They cannot move their eyes so they have adapted.
Why are hydrogen weaker bonds weaker than ionic and covalent ones?
They take less energy to break
How are cations and anions attracted to each other?
Through electrostatic attraction
Why do atoms bond?
To minimize energy and become more stable.
Mixtures
Two or more substances; do not undergo a chemical reactions; any combination of solids, liquid, and gasses
homogeneous mixture
same/uniformly distributed
What are the weakest bonds?
Van Der Waals Interactions
Growth and Development
We can inherit some traits based off of our DNA, like the pattern of growth.
Octet
When elements have eight electrons in their outer shell
Mettaloids
an element that has both metal and non metal properties; semiconductors; Boron (B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Tellurium (Te), Polonium (Po)
CHNOPS stands for....
atoms of life-Carbon (C), Hydrogen (H), Nitrogen (N), Oxygen (O), Phosporus (P), Sulfur (S), and Surenium (Se)
How are elements arranged on the periodic table?
by atomic number (ascending)
heterogeneous mixture
differently/not uniformly distributed
Bohr model
model of the atom in which electrons move rapidly around the nucleus in paths called orbits
Lewis diagrams
models of the atom that show only the valence electrons
Noble gasses
non-metals, group 18, the most non-reactive elements, 8 valence electrons
examples of heterogeneous mixtures
oil and water; cereal and milk; salad
electrostatic attraction
the attraction between positive and negative charges
Atomic number
the number of protons in the nucleus of an atom