Bio First Test Characteristics of Life/Elements/Atoms

heterotrophs

organisms that gain energy from the food they eat

autotrophs

organisms that gain energy from the food that they produce

homeostasis

the ability to maintain inner conditions that are suitable for life

poikilotherm

a cold blooded animal

homeotherm

a warm blooded animal

8 characteristics of life

- reproduction
- homeostasis
- made up of one or more cells
- growth and/or development
- reaction to stimuli
- organized system/cellular structuring
- obtaining and using energy
- dependent on environment

environmental stimuli

stimuli from the outside world (like temperature, air, water, sound, etc.)

internal stimuli

stimuli from the inside of an organism's body (like body temperature, sweating due to heat, etc.)

sexual reproduction

when a sperm cell and egg cells are required to create offspring

asexual reproduction

when only one cell can create offspring on its own

energy

the ability to make things change

organisms

living things

growth

when the amount of living material in an organism increases

development

all of the changes throughout an organism's life

scientific method steps

1. ask questions and observe
2. research
3. hypothesis
4. experiment
5. analyze data
6. hypothesis correct or incorrect
7. conclusion/organize all data, results
8. if hypothesis is incorrect then try again

independent variable

the variable that is changed/manipulated

dependent variable

the variable that is observed/measured/the data

control group/variable

a variable that is not changed/is in its original state (is used for comparison)

types of data organization

- graphs
- tables
- charts

what is the y axis in graphs

vertical axis/dependent variable (being observed)

what is the x axis in graphs

horizontal axis/independent variable (being changes)

quantitative data

data with numbers

qualitative data

data that is organized into charts, tables, and graphs

3 types of graphs

- line graph
- pie graph
- bar graph

bar graph use

to show a comparison of multiple objects

pie graph use

to show a comparison between different parts of a whole

line graph use

to show the relationship between variables

graphing steps

1. identify variables
2. determine the range
3. determine the scale
4. number and label each axis
5. plot the points
6. draw the graph
7. give the graph a title
8. write the key

3 states of matter

- solid
- liquid
- gas

atom

smallest unit of matter

element

an atom that is characterized by the amount of protons that it has in its nucleus

atomic number

the number of protons in an atom

atomic mass

the number of protons and neutrons combined (p+n = at. mass)

protons

parts of an atom that are located inside the nucleus (have a positive charge)

neutrons

parts of an atom that are located inside the nucleus (have no charge)

electrons

part of an atom that are located on the energy shells (have a negative charge)

energy shells

an orbit on which an electron orbits around a nucleus of an atom

matter

anything with mass and occupies space

pure substances

compounds or elements

compounds

substances that contain atoms from multiple elements (can be broken down)

elements

one type of atoms with the same atomic number (cannot be broken down)

mixtures

homogenous mixtures or heterogenous mixtures

homogenous mixtures

mixtures with one texture/composition is not visible/no visible pieces

heterogenous mixtures

mixtures with multiple textures/composition is visible/pieces are visible

molecules

two or more atoms together

groups

the vertical columns in the periodic table which determine how many electrons are in the last (valence) shell of an atom

periods

the horizontal rows in the periodic table which determine how many energy shells an atom has

valence shell

the last shell of an atom

octet rule

all atoms try to have 8 electrons in the last energy shell to be stable

exception to the octet rule

if there is only one energy shell then an atom needs 2 electrons to be stable

isotope

atoms of an element with identical properties that have a different mass due to the difference in the amount of neutrons

formula to the amount of electrons in each shell

2(n)² n = the shell number

chemical bond

an attempt to fill an atoms energy shell

ion

when an atom/molecule gains or loses an electron

cation

when an atom loses an electron (the atom becomes positively charged)

anion

when an atom gains an electron (the atom becomes negatively charged)

when an element has 1, 2, or 3 electrons in the last shell what does it do

it loses electrons (metal elements)

when an element has 5, 6, or 7 electrons in the last shell what does it do

it gains electrons (nonmetals)

electronegativity

property of an atoms to attract electrons (strength depends on the distance of the valence electrons from the nucleus and the atoms atomic number )

ionic bonds

happen between metals and nonmetals and are formed by the transfer of electrons (produces charged ions)

covalent bonds

happen between nonmetals and are formed by sharing electrons (like O2, CO2, etc.)

polar covalent bonds

a covalent bond where the electrons are unequally distributed causing one side of the molecule to be positively charged and the other negatively charged

nonpolar covalent bonds

a covalent bond where the electrons are equally distributed

hydrogen bonds

when a hydrogen atom with a slightly positive charge is attracted to an atom of a different element with a slightly negative charge