Chapter 2A Flashcards
What is matter?
Anything that takes up space and has volume and mass.
What is energy?
The ability to do work.
What are elements?
A substance that consists of only one type of matter.
Approximately how many elements are essential to life?
25
What are atoms?
Smallest unit of an element that still retains the characteristic of the element.
What are the three sub-atomic particles?
- Protons
- Neutrons
- Electrons
Protons charge, mass, and location
Positive, mass of one, inside the nucleus
Neutrons charge, mass, and location
No charge, mass of one, inside the nucleus
Electrons charge, mass, and location
Negative, mass of approx. 0, surrounding the nucleus
What is atomic number
The number of protons in the nucleus
What is mass number
The total number protons + neutrons
What are Ions?
An atom that has gained or lost electrons
What are isotopes?
Alternate forms of atoms
what is the atomic weight?
The average of all the different types of that element. (isotopes)
what are radioactive isotopes?
An unstable isotope
What are molecules?
Two or more combined atoms.
what are compounds?
Two or more combined atoms of different elements.
What are orbitals?
The path an atom can take around the nucleus.
How many electrons can be held in each orbital?
two
What are energy shells
where electrons can reside
How many electrons can be held in each energy shell
2n²
How does the position of an electron relate to
its energy level?
The closer to the nucleus the lower the energy
What are the valence shell and valence electrons?
The outermost occupied shell
What is electronegativity?
The ability of an element/atom to attract electrons
What are chemical bonds
What links atoms
What are the three types of chemical bonds
common in living systems?
- Ionic Bonds (Transfer electrons gain or loss)
- Covalent Bonds (share electrons)
- Hydrogen Bonds
Ionic bonds location and relative strength
are intermolecular and strong
covalent bonds location and relative strength
are intermolecular and strong
hydrogen bonds location and relative strength
they hold molecules together and are weak
what are nonpolar covalent bonds
sharing of electrons that is equally shared
what are polar covalent bonds
The nucleus of one atom has a stronger pull on the electron
What are the five life-supporting properties of water?
- Cohesive and adhesive
- many substances dissolve in water
- water regulates temperature
- water expands as it freezes
- water participates in life’s chemical reaction
What is cohesion
The attraction of water molecules to one another
what is adhesion
the attraction of water molecules to other substances other than water
What are solvents
a chemical in which other things dissolve
what are solutes
chemicals that dissolve in the solvent
what are solutions
the mixture of a solute dissolved in a solvent.
what is a hydrophobic substance
they repel water
what is a hydrophilic substance
it is attracted to water
What are chemical Reactions
The rearrangement of chemical bonds
What are reactants
A starting material in a chemical reaction
what are products
The results of a chemical reaction
What is the balanced chemical equation
for photosynthesis?
6CO2+6H2O→C6H12O6+6O2
What is pH
The power of hydrogen
What is the pH scale
A measurement of how acidic or basic a solution is
What is the equation for the dissociation of water?
H2O ⇌ H+ + OH-
What is an acid
when there are more hydrogen atoms then hydroxide
what is a base
when there are more hydroxide atoms then hydrogen
