Chapter 2- Chemistry Flashcards
what is the most common element by mass in the earth?
iron
What is the pH of milk?
slightly acidic
What is organic chemistry?
The study of the compounds that make up living organisms
All organic molecules contain which two elements?
Carbon and hydrogen
What qualities does matter have?
Take up space and have mass
What is matter made of?
Elements
What is an element?
A substance that cannot be broken down or transformed chemically
What is the smallest amount of an element called?
an atom
What are the rows of the period table called? What happens as you go left to right?
periods; atomic number increases
What does the period of an element tell you?
Number of shells it has
What are the columns of the periodic table called?
Groups
What does the group of an element tell you?
How many electrons it has in its valence shell
What are the four main elements in the human body?
oxygen, carbon, hydrogen, nitrogen
What two categories can all elements be divided into?
Metals and non metals
Do metals/non-metals tend to lose or gain electrons? What charge do they have?
metals: Lose- positive cation
mon: gain- negative anion
What is the basic building block of chemistry
atoms
What defines an element?
Number of protons
What is the atomic number?
Number of protons
What is atomic mass?
protons+neutrons (average of all isotopes)
What are isotopes?
Atoms that have the same atomic number but different number of neutrons
What are unstable isotopes called?
Radioisotopes
What are some uses of radioactive isotopes?
tracers, PET scans,
What does electronegativity of an atom mean?
The strength with which atoms attract other electrons
What is the valence of an atom?
the ratio with which it interacts with other atoms
Elements that have similar properties usually have the same number of?
Valence electrons
Metals have how many valence electrons?
1,2,3
What are the noble gases?
Helium, neon, argon, krypton, xenon
What determines the chemical behavior of an element?
number and arrangement of valence electrons
What is ground state?
lowest level energy of electrons closest to nucleus
Do elements prefer to be at excited or ground state?
ground
What happens when electrons shift to lower energy levels?
release light
Which color requires electron to drop most energy levels?
violet
What number of valence electrons have most reactive elements?
one or two more or less than a filled shell
What is the formula for glucose?
C6 H12 O6
What is molecular mass?
Sum of all mases of atoms in a molecule
What is molarity?
Number of moles of solute per liter
What are the types of bonds?
Covalent, ionic, hydrogen
What is a non polar covalent bond?
Equal sharing of electrons, electrically balanced
What is a polar covalent bond>?
One atom attracts shared electrons more than the other, resulting in one having a slightly positive and the other a negative charge
The atom that pulls shared electrons more towards it has more?
Electronegativity
What does an ionic bond result in?
2 ions that are attracted to each other (electrostatic)
What type of ion is an atom that loses electrons?
Cation
What is a polyatomic ion?
covalently bonded atoms that have a charge (OH)
Why does salt dissolve in water?
Water creates shell that prevents iconic association between NA and CL
Does the hydrogen in water have a negative or positive charge?
positive
How many other water molecules can one be bonded to?
4
What 6 qualities of water are because of its polarity?
liquid at room temp lose/gain heat slowly high vapor temp less dense when frozen fills vessels universal solvent
What is loss of water from leaves to prevent overheating?
Transpiration
Does water adhere or cohere to other substances?
adhere
what creates surface tension?
Cohesion at the surface
Where on plants do gases leave through?
stomata
solute v solvent
solute- substance being dissolved
solvent- dissolving agent
How are acids bases created?
water molecules dissociate into an equal number of hydrogen and hydroxide ions
Do acids release more hydrogen or hydroxide ions?
hydrogen
Do stronger or weaker acids dissociate completely in water?
stronger
What are buffers?
Regulate pH levels by taking up hydrogen or hydroxide ions
How much difference is there between one ph to the next?
x10
CO2 dissolved in sea water causes what?
carbonic acid and acidification
What are enantiomers?
isomers that are mirror images of each other
What are the 7 functional groups?
hydroxyl carbonyl carboxyl amino sulfhydryl phosphate methyl
What do hydroxyl groups do to organic molecules?
Increase solubility
Hydroxyl group
-OH
Carbonyl group
(C)–O
Carboxyl group
OOH
Amino group
-NH2
Sulfhydryl group
-SH
Phosphate group
OPO3 2-
methyl group
CH3
