2.1 Chem Review Flashcards
Define Isotopes
different forms of the same atom that vary in # of neutrons but have the same number of protons
How is carbon dating done?
By comparing the ratio of 14C and 12C in the atmosphere and in the fossil, therefore the amount of the isotope that did not decap can be determined
What is half-life?
half of the original concentration will go back to this form ( half of the original concentration will go back to this form after 5730 years later)
How can we use carbon dating in biology?
By studying the age of fossiles of extinct organism can help us understand how organisms have evolved
Define chemical reactivity
the ability to combine and to chemically bond with each other. Based on the # and spatial distribution of an atom’s electrons
Law of conservation
mass is not destroyed or created
What is a reversible reaction?
some products can be turned back into reactants
what is equilibrium?
back and forth balancing until a relative balance occurs
What law is used maintain the homeostasis of blood
Law of mass action; carbonic acid leaving the body as carbon dioxide gas (exhalation) leaves which drives the reaction to right
What are cations and anions?
Cations- positively charged ions
Anions- negative charged atoms
What are ionic bonds?
Forms between ions of opposite charges
What are electrolytes?
ions needed for nerve impulse conduction, muslce contractions and water balance
What are some examples of electrolytes?>
sodium, potassium and calcium
What are covalent bonds
Bonds that share electrons and are very strong due to their ability to make double and triple bonds
Why can’t nitrogen be used in the atmosphere?
Due to their triple bond which doesn’t allow it to break
What are polar covalent bonds?
electrons unequally shared which creates partially charged ions
Why is one electron more attracted to one molecule compared to another one?
Due to its stong electronegativity (attraction)
What are nonpolar covalent bonds
share electrons equally
What are hydrogen bonds?
weak between slighlty positive hydrogen atoms and slightly negative hydrogen atoms. commonly occurs between water molecules and zips together the DNA double helix
What are Van der Waals interaction
occur between any two or more molecules that are close to each other and dependent on slight fluctuations of electron densities; contributes to the structure of protein
Electronegativity chart to show polarity
0- nonpolar covalent
0.5- polar covalent
1.7 ionic bond
What does pH stand for
power of hydronium or hydrogen (chance of hydronium in a molecule)
acidity and ph connection
H+; a higher chance for the power of hydrogen
base and ph connection
a lower chanced for hydronium and hydrogen (OH-)
