Quiz 1 Flashcards
Science
Guided by natural law, testable against observable world, and tentative conclusions
comparative experiments
differences between samples or groups that may differ in multiple, unknown ways
controlled experiments
manipulate one or more factors from being tested
null hypothesis
no real difference between groups
alternative hypothesis
there is a real difference in the groups
statistical significance
probability that an observed difference is not due to chance alone. we will be willing to accept a 5% chance of rejecting a null hypothesis when it is actually true
levels of biological organization
biosphere, ecosystem, community, population, organism, organ systems, tissue, cell, organelle, molecule
what determines the identity of the element?
Protons determine the identity of an element (the atomic number)
chemical reactions
the changes in distribution of electrons between atoms
chemical bond
the attractive force that links atoms together
molecule
stable association of atoms
covalent bond
strong bonds that result from sharing of electrons between atoms (strong). Sharing of valence electrons (unpaired electrons). If the two elements are close to each other on the periodic table
ionic bond
electrons transferred from one atom to another, resulting in electrostatic attraction between oppositely charged ions. Formed when one atom gains and another one loses one or more electrons (strong). Huge electronegative difference (NaCl)
Hydrogen Bond
Electrostatic attraction between slightly positive charged H and negatively charged FON atoms (weak)
Van der Waals Interactions
Transient electrostatic attractions between oppositely charged atoms. This only has non polar covalent bonds (very weak) non polar bonds are very weak. When there are many they become strong
How many covalent bonds can hydrogen make?
1 bond because they only have 1 electron
How many covalent bonds can Oxygen have?
2
How many covalent bonds can Carbon have?
They can have 4
electronegativity
attractive force that an atomic nucleus exerts on electrons of another atom
polar covalent bond
unequal sharing of electrons due to differences in electronegativities of the atoms
ion
atom that loses/gains one or more electrons. Cation is positively charged while anion is negatively charged
dipole
separation of opposite electric charges. When the main element has a weaker electronegativity than the other elements have lower electronegativities (o-c-o). The oxygens are moving away from the oxygen.
second law of thermodynamics
when an energy transformation occurs there is an increase in entropy
Is water a solvent or a solute?
it is a solvent because it is what dissolves the solvent. Ex. Water dissolves salt (salt is the solute)