Quiz 1
What are the six steps of the scientific method
1: Observe
2: Form a question
3: Form a hypothesis
4: Design an experiment
5: Collect Data
6: Interpret Data/Draw a conclusion
What are the three subatomic particles of an atom and what are their charges?
Proton - positive
Neutron - neutral
Electron - negative
Define a chemical compound
A substance that is formed by the chemical combination of two or more elements
What is polarity? Where do we see this in water?
When the distribution of electrons is uneven in a molecule, so one or more atoms pulls the electrons closer to itself.
In H2O, the Oxygen creates polarity by attracting electrons towards it.
What are the two ions produced by water molecules in an acid-base reaction
H+ (hydrogen ion) and OH - (hydroxide ion)
What is an independent and dependent variable
independent - the variable that is deliberately changed
dependent - the variable that changes in response to the independent variable (the outcome)
What is an element
A pure substance
Electrons found in the outer shell of an atom. They are the electrons that form bonds with other atoms.
What is the difference between cohesion and adhesion in water molecules?
- Cohesion: attraction between molecules of the same substance
-Adhesion: attraction between molecules of different substances
Define pH
The concentration of hydrogen ions in a solution
All living things have the ability to ________________________________________. Some organisms simply increase in size, while others go through the process of development.
Grow and Develop
What is the atomic and mass number of an element?
Atomic - the amount of protons in an atom
Mass - the amount of protons and neutrons in an atom
What is an ionic bond? What are the resulting ions?
A bond formed when one or more electrons are transferred from one atom to another.
Anion - positively charged atom
Cation - negatively charged atom
What is heat capacity and why is the heat capacity of water important to the survival of living organisms
Heat capacity - the amount of energy needed to raise a molecule's temperature
- water takes a significant amount of energy to raise its temperature. This means water can take a lot of heat without damaging the living organisms within it
What is an acid and what is a base? What pH range is considered an acid, what range is considered a base?
-Acid: any compound that releases hydrogen ions into a solution (pH 1-6)
-Base: Any compound that produces OH- ions into a solution (pH 8-14)
Name the Eight Characteristics of living things
-grow and develop
-use a universal genetic code
-maintain an internal balance
-made up of cells
-respond to the environment
-evolve
-reproduce
-Use materials for energy
What is an isotope? Why can they be radioactive?
Atoms of the same element that have different numbers of neutrons. The excess neutrons make the nucleus unstable and neutrons are shot out from it.
Why are weak interactions (bonds) important for living things?
-Momentary interactions in a cell allow it to send signals and copy information
-van der waals forces cause a slight attraction due to close proximity between atoms (gecko foot)
-hydrogen bonds form water molecules
Define solute and solvent
Solute - substance that is dissolved in a solution
Solvent - substance in which the solute dissolves
What is a buffer and why is it important?
Weak acids or bases that can react to strong acids or bases to prevent dramatic changes to pH
Importance: It helps maintain homeostasis