Chem. Lecture 7/19 – Flashcards

question
define accuracy
answer
accuracy = closest to the actual #; has the smallest error
question
define precision
answer
precision = how consistent a set of measurements is
question
equation for calculating error
answer
error = measured - accepted answer
question
equation for percent error
answer

percent error =           error

                             ___________   x 100

                               accepted

question
equation for converting Celsius to Kelvin
answer

Celsius → Kelvin

 

Kelvin = ºC + 273.15

question
equation for converting Kelvin to Celsius
answer

Kelvin → Celsius

 

Celsius = ºKelvin - 273.15

question
equation for converting Celsius to Fahrenheit
answer

Celsius → Fahrenheit

 

Fahrenheit = 9/5 x ºC + 32º

question
equation for converting Fahrenheit to Celsius
answer

Fahrenheit → Celsius

 

Celsius = 5/9 (ºF - 32)

question
What was Thales theory about matter?
answer
Thales (ancient Greek, "1st" to explore this concept) thought that everything was made up of water; that water was the basic element.
question
What was Empedocoles theory about matter?
answer
Empedocoles agreed with Thales that water was an element, but believed it was one of 4 - earth, air, fire, and water (like the Last Airbender...haha). He believed that all things were comprised of combinations of these elements, that were effected by the forces of harmony and discord.
question
What was Democratus' theory about matter?
answer
Democratus, by observing grains of sand, theorized that matter is made up of tiny, indestructable particles, but that there is a minimum size (the atom) and that it cannot get any smaller
question
What was Socrates' theory about matter?
answer
Socrates agreed with Democratus that everything is made up of small, indestructable particles, but disagreed about the minimum size. He believed that there is no minimum size, that matter can continuously be broken down; the CONTINUOUS THEORY. This became the norm until after the "Dark Ages of Chem.", and scientists began to reavaluate Democratus' ATOM THEORY.
question
Who brought back Democratus' atom particle concept, and what was his theory?
answer

Boyle (English) in the 1660s theorized that gas made up of little particles with space in between them that could be pressed together.

Essentially Boyle was the 1st to re-examine Democratus' concept of an atom/particle after years of the Continuous Theory being the accepted scientific norm.

question
Explain Bernoulli's theory about particles
answer
Bernoulli (1730s, Italian) theorized that pressure is caused by particle/atom collisions
question
What theory did Lavoisier disprove, and how did he do it?
answer

Before Lavoisier, many believed in the existance of "phlogiston", an element of sorts that was present in everything, and was released when things burned. This theory was "confirmed" by comparing the weight of a block of metal to the weight of that same metal sample after being burned; in such experiments, the burned sample ("calx") would weigh more - thus, they believed it had actually changed forms.

Lavoisier, suspicious of this theory, revised the experiment. He covered both the samples with glass hoods before weighing them, and found that they ended up weighing the same. Therefore, the LAW OF THE CONSERVATION OF MASS was developed - matter is neither created nor destroyed.

question

What was Dalton's 1st law?

What is accurate and inaccurate?

answer

Dalton's 1st Law

 

1.) Each element is made from tiny, indestructable atoms

(similar to Democratus!)

 

However, the truth is, atoms are NOT indestructable; they can in fact be destroyed.

Also, an atom is not the smallest particle; smaller particles exist (protons, electrons, etc.)

question

What is Dalton's 2nd law?

What is accurate and inaccurate?

answer

Dalton's 2nd Law

 

2.) All atoms of an element are identicle.

 

FALSE! Not all atoms are identicle; isotopes exist.

question

What is Dalton's 3rd Law?

What is accurate and inaccurate?

answer

Dalton's 3rd Law

3.) Elements combine in fixed ratios to form compounds

This is TRUE :)

question

What is Dalton's 4th Law?

What is accurate and inaccurate?

answer

Dalton's 4th Law

 

4.) In reactions, atoms are just rearranged, not created or destroyed.

 

This is partially true; for the most part, atoms cannot be created or destroyed....except in radioactivity and nuclear reactions

question
Who experimented with the "cathode ray tube"?
answer
J.J Thompson
question
Who discovered the electron?
answer
J.J Thomas discovered the electron
question
What did the cathode ray tube experiment prove?
answer
J.J Thompson's cathode ray tube experiment proved that negatively charged particles gravitate toward positively charged cathodes - and because the beam of light created in the tube was made up of particles/ atoms, he determined that all atoms have some negative charge (electrons!)
question
What was Millikan's model of the atom?
answer

Millikan (American) called his model of the atom the

"PLUM PUDDING" model, with little "raisins" (electrons) randomly distributed in a bunch of "positive stuff" within the atom

question
What did Rutherford want to know and how did he experiment to find an answer? What did he discover?
answer

Rutherford (New Zealander) wanted to know how big atoms are.

To determine this, he devised the GOLD FOIL EXPERIMENT.

 

Flattened out a sheet of gold, reeeeally thin. Shot alpha particles (+ charge) of Helium at the sheet of gold, which had a curved screen behind it. The alpha particles produced light, which he expected to shine directly on the spot of the screen that it was aimed at. Instead, it deflected to cover almost the entire screen, and some of it reflected back.

 

The result of this experiment was the discovery that atoms have small, dense, positive nucleuii (nucleus) and are mostly empty space

question
What did Rutherford's model of the atom look like?
answer

Rutherford's model of the atom

 

Small, dense, positively charged nucleus in the center - protons only in the nucleus

 

Outside of nucleus there is mostly empty space, with randomly scattered electrons (negative charge)

question
What is a neutron's charge?
answer
A neutron is neutral; it has a charge of 0.
question
What is a proton's charge?
answer
A proton has a positive charge; +1.
question
What is an electron's charge?
answer
An electron has a negative charge; -1.
question
Who discovered the neutron?
answer
Chadwick discovered the neutron
question
Where are protons located?
answer
Protons (positive charge) are located in the nucleus
question
What does the atomic # of an element tell you?
answer
The atomic # of an element tells you the NUMBER OF PROTONS
question
What does the mass # of an element on the periodic table tell you?
answer

The mass # of an element on the periodic table tells you the number of protons + neutrons within 1 atom of that element; the mass.

mass number = # of protons + # of neutrons

So, knowing the # of protons from the atomic #, the number of neutrons can be deduced. And because the number of electrons is always equal to the number of protons, it is easy to calculate the quantities of all 3 within 1 atom.

question
The number of electrons is always equal to....
answer
The number of electrons always = to the number of protons
question
The number of protons is always equal to.....
answer
The number of protons is always = to the number of electrons
question
Define isotopes
answer

Isotopes are atoms with the same number of protons, but different numbers of neutrons.

In other words, they have the same atomic # but different mass #s than you would find on the periodic table.

question
What is atomic mass and how is it calculated?
answer

Average Atomic Mass is the sum of the abudance x isotopes. It is what is used to create the mass #s used on the periodic table.

For example, 75% of Cl. atoms in the world have a mass of 35, and 25% have a mass of 37.

(.75 x 35) + (.25 x 37)

= 35.5

the atomic mass of Cl on the periodic table

question
Define ion
answer
ion - an atom that has gained or lost 1 or more electrons
question
Define cation
answer
Cation - A positive ion; it has lost electrons (lost some negative charge, therefore becoming positive)
question
Define anions
answer
Anions - negative ions; gained electrons
question
Compare atoms vs. molecules
answer

Atoms - smallest particle of an element that exists ; still has chem. properties of that element.

;

Molecule - smallest particle of a compound that exists and still has chemical properties of that compound. Consists of more than 1 atom bonded together

question
What happens to the protons and electrons of an atom when neutral?
answer
When neutral, atoms have equal numbers of protons and electrons
question
What is a diatomic element?
answer
A diatomic element has more than 1 atom of the same type of element bonded together (therefore it is still an element; if they were different it would be a compound.)
question
What are the 7 diatomic elements?
answer

Dr. Br I N Cl H O F

;

Br = Bromine

I = Iodine

N = Nitrogen

Cl = Chlorine

H = Hydrogen

O = oxygen

F = Fluorine

question
Who was the 1st to organize a periodic table of the elements, and how was it organized?
answer
Mendeleev was the 1st to attempt to organize a periodic table. He organized it by mass (the proton hadn't been discovered yet.)
question
Who organized the periodic table as it appears today?
answer
Mosely reorganized Mendeleev's periodic table to account for the discovery of the protons. It is organized by atomic #.
question
The horizontal rows on the periodic table are called....
answer
horizontal rows = periods
question
The vertical columns on the periodic table are called.....
answer
vertical columns = groups
question
What are the elements in group 1 on the periodic table called?
answer
Group 1 = Alkali metals
question
What are the elements in group 2 of the periodic table called?
answer
Group 2 = Alkaline earth metals
question
What are the elements in group 17 of the periodic table called?
answer
group 17 = Halogens (they make salts)
question
What are the elements in group 18 of the periodic table called?
answer

group 18 = Noble gases

;

(hardly interact with other elements; they're too "noble" for the "commoners")

question
The left side of the periodic table (to the left of the little 'staircase') contains...
answer
Left side of the periodic table = metals
question
The elements on the right side of the periodic table (to the right of the little "staircase") are....
answer
The elements on the right side are non-metals
question
The elements that lie upon the staircase on the periodic table are called....
answer
On the staircase = metalloids
question
Groups 3 - 12 on the periodic table are....
answer
Groups 3-12 are the Transition Metals
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question
define accuracy
answer
accuracy = closest to the actual #; has the smallest error
question
define precision
answer
precision = how consistent a set of measurements is
question
equation for calculating error
answer
error = measured - accepted answer
question
equation for percent error
answer

percent error =           error

                             ___________   x 100

                               accepted

question
equation for converting Celsius to Kelvin
answer

Celsius → Kelvin

 

Kelvin = ºC + 273.15

question
equation for converting Kelvin to Celsius
answer

Kelvin → Celsius

 

Celsius = ºKelvin - 273.15

question
equation for converting Celsius to Fahrenheit
answer

Celsius → Fahrenheit

 

Fahrenheit = 9/5 x ºC + 32º

question
equation for converting Fahrenheit to Celsius
answer

Fahrenheit → Celsius

 

Celsius = 5/9 (ºF - 32)

question
What was Thales theory about matter?
answer
Thales (ancient Greek, "1st" to explore this concept) thought that everything was made up of water; that water was the basic element.
question
What was Empedocoles theory about matter?
answer
Empedocoles agreed with Thales that water was an element, but believed it was one of 4 - earth, air, fire, and water (like the Last Airbender...haha). He believed that all things were comprised of combinations of these elements, that were effected by the forces of harmony and discord.
question
What was Democratus' theory about matter?
answer
Democratus, by observing grains of sand, theorized that matter is made up of tiny, indestructable particles, but that there is a minimum size (the atom) and that it cannot get any smaller
question
What was Socrates' theory about matter?
answer
Socrates agreed with Democratus that everything is made up of small, indestructable particles, but disagreed about the minimum size. He believed that there is no minimum size, that matter can continuously be broken down; the CONTINUOUS THEORY. This became the norm until after the "Dark Ages of Chem.", and scientists began to reavaluate Democratus' ATOM THEORY.
question
Who brought back Democratus' atom particle concept, and what was his theory?
answer

Boyle (English) in the 1660s theorized that gas made up of little particles with space in between them that could be pressed together.

Essentially Boyle was the 1st to re-examine Democratus' concept of an atom/particle after years of the Continuous Theory being the accepted scientific norm.

question
Explain Bernoulli's theory about particles
answer
Bernoulli (1730s, Italian) theorized that pressure is caused by particle/atom collisions
question
What theory did Lavoisier disprove, and how did he do it?
answer

Before Lavoisier, many believed in the existance of "phlogiston", an element of sorts that was present in everything, and was released when things burned. This theory was "confirmed" by comparing the weight of a block of metal to the weight of that same metal sample after being burned; in such experiments, the burned sample ("calx") would weigh more - thus, they believed it had actually changed forms.

Lavoisier, suspicious of this theory, revised the experiment. He covered both the samples with glass hoods before weighing them, and found that they ended up weighing the same. Therefore, the LAW OF THE CONSERVATION OF MASS was developed - matter is neither created nor destroyed.

question

What was Dalton's 1st law?

What is accurate and inaccurate?

answer

Dalton's 1st Law

 

1.) Each element is made from tiny, indestructable atoms

(similar to Democratus!)

 

However, the truth is, atoms are NOT indestructable; they can in fact be destroyed.

Also, an atom is not the smallest particle; smaller particles exist (protons, electrons, etc.)

question

What is Dalton's 2nd law?

What is accurate and inaccurate?

answer

Dalton's 2nd Law

 

2.) All atoms of an element are identicle.

 

FALSE! Not all atoms are identicle; isotopes exist.

question

What is Dalton's 3rd Law?

What is accurate and inaccurate?

answer

Dalton's 3rd Law

3.) Elements combine in fixed ratios to form compounds

This is TRUE :)

question

What is Dalton's 4th Law?

What is accurate and inaccurate?

answer

Dalton's 4th Law

 

4.) In reactions, atoms are just rearranged, not created or destroyed.

 

This is partially true; for the most part, atoms cannot be created or destroyed....except in radioactivity and nuclear reactions

question
Who experimented with the "cathode ray tube"?
answer
J.J Thompson
question
Who discovered the electron?
answer
J.J Thomas discovered the electron
question
What did the cathode ray tube experiment prove?
answer
J.J Thompson's cathode ray tube experiment proved that negatively charged particles gravitate toward positively charged cathodes - and because the beam of light created in the tube was made up of particles/ atoms, he determined that all atoms have some negative charge (electrons!)
question
What was Millikan's model of the atom?
answer

Millikan (American) called his model of the atom the

"PLUM PUDDING" model, with little "raisins" (electrons) randomly distributed in a bunch of "positive stuff" within the atom

question
What did Rutherford want to know and how did he experiment to find an answer? What did he discover?
answer

Rutherford (New Zealander) wanted to know how big atoms are.

To determine this, he devised the GOLD FOIL EXPERIMENT.

 

Flattened out a sheet of gold, reeeeally thin. Shot alpha particles (+ charge) of Helium at the sheet of gold, which had a curved screen behind it. The alpha particles produced light, which he expected to shine directly on the spot of the screen that it was aimed at. Instead, it deflected to cover almost the entire screen, and some of it reflected back.

 

The result of this experiment was the discovery that atoms have small, dense, positive nucleuii (nucleus) and are mostly empty space

question
What did Rutherford's model of the atom look like?
answer

Rutherford's model of the atom

 

Small, dense, positively charged nucleus in the center - protons only in the nucleus

 

Outside of nucleus there is mostly empty space, with randomly scattered electrons (negative charge)

question
What is a neutron's charge?
answer
A neutron is neutral; it has a charge of 0.
question
What is a proton's charge?
answer
A proton has a positive charge; +1.
question
What is an electron's charge?
answer
An electron has a negative charge; -1.
question
Who discovered the neutron?
answer
Chadwick discovered the neutron
question
Where are protons located?
answer
Protons (positive charge) are located in the nucleus
question
What does the atomic # of an element tell you?
answer
The atomic # of an element tells you the NUMBER OF PROTONS
question
What does the mass # of an element on the periodic table tell you?
answer

The mass # of an element on the periodic table tells you the number of protons + neutrons within 1 atom of that element; the mass.

mass number = # of protons + # of neutrons

So, knowing the # of protons from the atomic #, the number of neutrons can be deduced. And because the number of electrons is always equal to the number of protons, it is easy to calculate the quantities of all 3 within 1 atom.

question
The number of electrons is always equal to....
answer
The number of electrons always = to the number of protons
question
The number of protons is always equal to.....
answer
The number of protons is always = to the number of electrons
question
Define isotopes
answer

Isotopes are atoms with the same number of protons, but different numbers of neutrons.

In other words, they have the same atomic # but different mass #s than you would find on the periodic table.

question
What is atomic mass and how is it calculated?
answer

Average Atomic Mass is the sum of the abudance x isotopes. It is what is used to create the mass #s used on the periodic table.

For example, 75% of Cl. atoms in the world have a mass of 35, and 25% have a mass of 37.

(.75 x 35) + (.25 x 37)

= 35.5

the atomic mass of Cl on the periodic table

question
Define ion
answer
ion - an atom that has gained or lost 1 or more electrons
question
Define cation
answer
Cation - A positive ion; it has lost electrons (lost some negative charge, therefore becoming positive)
question
Define anions
answer
Anions - negative ions; gained electrons
question
Compare atoms vs. molecules
answer

Atoms - smallest particle of an element that exists ; still has chem. properties of that element.

;

Molecule - smallest particle of a compound that exists and still has chemical properties of that compound. Consists of more than 1 atom bonded together

question
What happens to the protons and electrons of an atom when neutral?
answer
When neutral, atoms have equal numbers of protons and electrons
question
What is a diatomic element?
answer
A diatomic element has more than 1 atom of the same type of element bonded together (therefore it is still an element; if they were different it would be a compound.)
question
What are the 7 diatomic elements?
answer

Dr. Br I N Cl H O F

;

Br = Bromine

I = Iodine

N = Nitrogen

Cl = Chlorine

H = Hydrogen

O = oxygen

F = Fluorine

question
Who was the 1st to organize a periodic table of the elements, and how was it organized?
answer
Mendeleev was the 1st to attempt to organize a periodic table. He organized it by mass (the proton hadn't been discovered yet.)
question
Who organized the periodic table as it appears today?
answer
Mosely reorganized Mendeleev's periodic table to account for the discovery of the protons. It is organized by atomic #.
question
The horizontal rows on the periodic table are called....
answer
horizontal rows = periods
question
The vertical columns on the periodic table are called.....
answer
vertical columns = groups
question
What are the elements in group 1 on the periodic table called?
answer
Group 1 = Alkali metals
question
What are the elements in group 2 of the periodic table called?
answer
Group 2 = Alkaline earth metals
question
What are the elements in group 17 of the periodic table called?
answer
group 17 = Halogens (they make salts)
question
What are the elements in group 18 of the periodic table called?
answer

group 18 = Noble gases

;

(hardly interact with other elements; they're too "noble" for the "commoners")

question
The left side of the periodic table (to the left of the little 'staircase') contains...
answer
Left side of the periodic table = metals
question
The elements on the right side of the periodic table (to the right of the little "staircase") are....
answer
The elements on the right side are non-metals
question
The elements that lie upon the staircase on the periodic table are called....
answer
On the staircase = metalloids
question
Groups 3 - 12 on the periodic table are....
answer
Groups 3-12 are the Transition Metals
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