Chapter 2 Flashcards by Jennifer Togun

uniiverse is composed of
________

matter

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Matter is found on Earth in what three physical states?

solid, liquid, and gas.

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Define Matter

anything that exhibit:
– Inertia: resistance to change in position
– occupies space
– has mass

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What is the difference b/w MASS and WEIGHT

MASS: how much matter is in an object
WEIGHT: how hard gravity pulls an object

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What do we use to organize our understanding of
matter?

The periodic table of the elements

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What is the fundamental unit of matter?

atoms

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There are ___ naturally occurring elements, but only __ are typically used by living cells

92; 25

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What are atoms?

the smallest units that retain all properties of their type of matter

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T or F: All matter consists of chemical elements

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Elements are listed in order of?

atomic number (# of protons)

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Each atom of an element is composed of?

protons, neutrons, and electrons

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T/F Your weight is same wherever you go

FALSE, your mass is the same wherever you go

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When atoms are bonded together they form what?

stable molecules

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The atomic weight of an element corresponds to?

of protons + # of neutrons

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__ elements are required in small quantities (micronutrients), and
__ are required in only tiny amounts

7; 14

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T/F Elements are essential to life

True

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How many of the of the 92 known elements make
up the bulk (mass) of living cells and what are they?

Oxygen
carbon
hydrogen
nitrogen

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what is the difference between micronutrients and trace elements?

micronutrients are required in small quantities while trace elements are required in only tiny amounts.

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name the 7 micronutrients:

calcium
phosphorus
potassium
sulfur
sodium
chlorine
magnesium

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What are the following elements considered as?
boron
chromium
cobalt
copper
fluorine
iodine
iron
manganese
molybdenum
selenium
silicon
tin
vanadium
zinc

Trace elements

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*Located in nucleus

*The number of
_______ determines
the chemical element

protons

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Nitrogen Atom:
7 protons
7 neutrons
7 electrons

What is the atomic weight?

Atomic weight = Protons + Neutrons
7 protons + 7 neutrons = 14

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*Located in nucleus

The number of
________ determines
the isotope

neutrons

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T/F Ions vary in the number of electrons in the
electron cloud

True

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define isotopes

variants of an element that differs in their number of neutrons.

T or F Isotopes are less stable and may decay over time, emitting radiation

What happens when an atom loses electrons?

it becomes electrically charged

In a chemical reaction, atoms do what?

gain, lose, or share electrons

What are charged atoms called?

Ions (can be positive or negative)

Nitrogen Ion: 7 protons 8 neutrons 10 electrons If a nitrogen atom gains 3 electrons, is it positively or negatively charged?

Negatively charged (Anion)

What is it called when Electrons are arranged in electron shells corresponding to different energy level?

Electronic Configurations

involve the transfer of one or more electrons from one atom to another.

ionic bonds

define covalent bonds

involve the sharing of one or more electrons between atoms.

In ionic bonds, is the receiving atom positively or negatively charged? Donating atom?

Receiving: Negative Donating: Positive

How are Ionic bonds held together?

by attraction of opposite charges.

If a nitrogen atom gains 3 electrons, does it have a greater mass than before?

No, the mass is the same because electrons have no mass

1st orbital = can only take ___ electrons 2nd orbital = can take max of ___ electrons 3rd orbital = can take max of 8 electrons 4th orbital = can take max of __ electrons 5th orbital = can take max of __ electrons

1st orbital = can only take 2 electrons 2nd orbital = can take max of 8 electrons 3rd orbital = can take max of 8 electrons 4th orbital = can take max of 18 electrons 5th orbital = can take max of 32 electrons

what is the difference between polar and nonpolar covalent bonds?

nonpolar is the equal sharing of electrons while polar is the unequal sharing of electrons

What are the strongest of the chemical bonds?

Covalent bonds

Bonds formed between C, N, O, P, H, S in all macromolecules such as proteins, carbohydrates, nucleic acids and lipids are what type of bonds?

covalent bonds

which covalent bonds are stronger between polar and nonpolar?

Nonpolar because the electrons are shared equally

What do the polar covalent bonds in water mean?

Uneven distribution charger - Oxygen is more negative and hydrogens are more positive

In the polar covalent bond of water what charge do oxygen and hydrogen have?

Oxygen is more negative Hydrogens are more positive.

The weak attractions between polar molecules

Hydrogen bonds

Hydrogen bonds hold ______(code of Life) together.

DNA

The polar nature of water means that water forms what type of bonds?

hydrogen bonds

Why is water so suitable for life?

Unique properties make it solid, liquid, or gas

What happens as water freezes?

stable hydrogen bonds hold molecules apart

In liquid water, hydrogen bonds constantly do what?

break and re-form

Does a chunk of ice or an equal volume of liquid water have fewer water molecules?

A chunk of ice

T or F Chemical reactions can rearrange matter but cannot create or destroy matter?

True

Which bonds are responsible for stable structures of proteins and nucleic acids?

Hydrogen bonds

Define Synthesis Reactions (Anabolism)

when atoms, ions, or molecules combine to form new, larger molecules

________ (what goes in) are transformed into __________ (what comes out) through __________ reactions.

reactants products water

Reactants and products are on what side of a chemical reaction?

Chemical reactions are written with the reactants on the left and the products on the right

what donates H+ (Hydrogen ion) when dissolved in water? HCl = H+ + Cl-

Acids

What is the synthesis of molecules in a cell

Anabolism

A (atom, ion, or molecule A) + B (atom, ion, or molecule B) = AB (New molecule) Is this a Synthesis or Decomposition rxn?

Synthesis

what accepts H+ when dissolved in water and/or can increase the concentration of OH- (hydroxyl ions? NaOH = Na+ + OH-

bases

AB (New molecule) = A (atom, ion, or molecule A) + B (atom, ion, or molecule B) What reaction is this?

Decomposition

when a molecule is split into smaller molecules, ions, or atoms

Decomposition

*_________ is the decomposition reactions in a cell

catabolism

Zest and Sharpness of food flavor is often due to ______

acid

what does the pH scale measure?

Measures H+ concentration of fluid

How do scientists indicate how strong or weak an acid or base is?

The pH scale

fill in below: 0---------------------7-------------------14 ______ ________ ________

0---------------------7-------------------14 acidic neutral basic

Each number in the pH scale represents what?

tenfold change in H+ ion concentration

Change of 1 pH on scale means ___X change in H+ concentration e.g. A change in pH from 8 to 10 = 100X stronger base

10X

Organic compounds ALWAYS contain what?

carbon and hydrogen

The amount of H+ in a solution is expressed as what?

what is the pH equation?

pH = −log[H+]

What do inorganic molecules lack?

carbon

Increasing [H+], increases _____ Increasing [OH−] increases ________

acidity alkalinity

How are polymers made?

by stringing together many smaller molecules called monomers

Most organisms grow best between pH of what?

6.5 and 8.5

are carbon-based molecules

organic compounds

What 2 things happens in a dehydration reaction?

- Links two monomers together - Removes a molecule of water

all anabolic reactions are what?

dehydration

what process is this? *Breaks bonds between monomers * Adds a molecule of water * Reverses the dehydration reaction

hydrolysis

Chapter 2 Flashcards

(79 cards)