Semester Questions Flashcards
What is something that helps explain why things happen?
Scientific Theories and Testable Hypothesis
Potassim bromate acts by oxidizing the
gluten and cross-linking tyrosine (an amino acid)
units of the protein molecule, enabling the dough
to retain gas better.
This is best classified as what?
A theory
A scientist wonders if sodium bromate
might cross-link separate tyrosine
molecules, forming a dimer
This is best classified as
A hypothesis
Dough to which potassium bromate
has been added rises better, producing a
lighter, larger loaf
This is best classified as
An observation
What is a scientific model?
a scientific theory
Law of the conservation of Mass
matter is neither created nor destroyed during a chemical change (and hence its mass remains constant)
Law of Definite Proportions
A compound always contains the same elements in certain definite proportions by mass and in no other (also know as the law of constant composition)
Law of Multiple Proportions
Elements might combine in more than one set of proportions to form different compounds. Proportions for different compounds of the same elements are related through simple whole number ratios.
How would you write a nuclear symbol for an atom/ion containing 27 protons, 33 neutrons, and 25 electrongs
60 on top with 27 on bottom and a plus two charge to the right
What is electricity? How is it explained on a molecular level?
The flow of a charge / either with electrons / or charged atoms
What did JJ Thomson’s Cathode ray tube experiment discover?
Charge of the electron
The point of Robert Millikan’s oil drop experiment?
Learned how to measure the charge and mass of an electron
The point of Eugen Goldsteins discharge tube experiment
positive ions have variable mass and are much heavier than the electron
Rutherfords gold foil experiment point
The majority of the atom is empty space and a small amount of of the mass is in the nucleus
what is a Covalent bond?
A bond that involves the sharing of electron pairs between atoms