Chem final

Chemistry

the study of matter and the changes that it undergoes

Scientific model

A workable explanation descripton or representation of a phenomenon in nature

What can scientific models be expressed as?

Mathematical formulas, physical representations, pictures

what does a naturalistic scientist believe?

that science can explain everything we see in this world

example of Biblical world view

creation (goodness), fall (brokennness), Redemtion (jesus), and Restoration (hope).

example of a naturalistic world view

the big bang theory

Qualitative Data

is desciptive and focuses on characteristics (uses 5 senses to answer how and why questions)

Quantitative Data

measures quantities using #s and mathamatical units.

What is TRUE about scientific laws?

They are changeable

Entropy

The measure of the dispersal of energy in a system

What does a model need to be in order for it to be affective?

It needs to be workable

Dependent Variables

A dependent Variable is NOT controlled by scientists (it is the variable being tested)

Independent Variable

Is controlled by the scientists (the control is not manipulated by the scientist)

You notice that your stomach bothers you when you drink coffee first thing in the

morning, but it doesn’t bother you when you drink milk or water first in the morning. You

think that it’s because coffee is more acidic. So you add baking soda to one sample of

coffee, brew another sample with eggshells, add milk of magnesia to a third, and leave

the fourth alone. When you drink the four beverages first thing in the morning, testing a

different sample each day, the last sample is the only one that still irritates your

stomach.

What do we call the coffee sample that was left alone?

The control or control group

Dependent or independent

it is a independent Variable

What do we call each of the other samples?

Experimental group / treatment group

What is the independent variable?

the independent variable is the substance that was added to the coffee to reduce the acidity.

Whay are 2 classifications of matter

Physical and chemical

Conductivity

The physical property of matter that describes its ability to conduct electricity

malleability

The physical property of matter that describes its ability to be molded and hammered into sheets.

Density

The amount of matter packed into a given volume

2 categories of matter

Pure substances and mixtures

what kind of milecule is Hydrogen, nitrogen, fluorine, and bromine

They are all diatomic molecules (dia means 2 ) they each have 2 atoms bonded together.

heat

The movement of thermal energy

First law of Thermodynamics

Called the Law of Conservation of energy and it says energy can not be created or destroyed it can only be transformed.

How many oxygen atoms are in Al(SO4)2

8

What is 196K in celsius

Formula (TC = TK - 273.15) so plug in 196 for TK and you will get -77 C which is your answer.

Kinetic Molecular theory

a theory that describes the movement of particles in matter

What is the movement of particles in Solids?

The particles are very close and really only vibrate in place

What is the movement of particles in Liquid?

also close but enough room in order to still be able to slide past each other and have space for liquid to flow between.

What is the movement of particles in Gas?

The particles are spaced out and can move freely and very quickly

What is the movement of particles in plasma?

The particles are very far apart allowing for the particals to move as quickly as gases but with the difference being that its atoms are ionied ( meaning electrically charged

Measurement

The act of comparing an unknown quantity to a standard unit

How many fundemental SI units are there

7

• Meter

• Kilogram

• Second

• Ampere

• Kelvin

• mole

• candela

442 Meters in kilometers?

(1 Km = 1000 meters) so you have to divide 442 by 1000 to get .442 Km

When determining significant figures in multiplication and division problems, the

answer cannot contain more significant figures than the measurement with the least

number of significant figures.

.00400320 has how many significant figures?

6 as you only start counting from the number after the 0s

30. Testing has shown that 65.80% of chlorine exists as Cl-35 (34.969 u) and that

34.20% of chlorine exists as Cl-37 (36.966 u). Calculate chlorine’s atomic mass.

(.6580)(34.969) + (0.3420)(36.966) = 35.651974 u

Atom

The smallest particle capable of chemical interactions

The 3 major atomic particales ( lightest to heaviest)

Electron, Proton , and Neutron

What is the isotopic notation for an atom that has 22 protons, 35 neutrons, and 22 electrons?

22 + 35 = 57 isotopic notation is 57/22 Ti

Continuous theory of matter

The belief that matter was made of separate discrete particles

Law of multiple proportions

When 2 electrons create 1 compound

Law of definite Proportions

A chemical compound always contains the same elements in the same fixed proportion by mass no matter where the compound comes from.

Atomic number

the number of protons in the nucleus of an atom

What is Z in atomic notation

represent the atomic number

Niels Bohr

Niels Bohr proposed the concept of principal energy levels, which he envisioned

as a set of circular tracks on which electrons orbited.

what is highest energy level a atom can have at ground state

7

Wave particle model of the electrons

electrons do not behave only like particles or only like waves ( they exhibit both wave like and particle like properties

What is the pattern for colored lines that was discovered while analyzing light

produced by heated elements?

Line emission spectrum

Photon

a particle or quantum of light

Fromula to determine # of electrons in the energy level

2(n) squared

How many electrons can the d sublevel hold

10

How many electrons are present in the third principal energy level in an atom with the full capacity of electrons?

1S2 + 2S6 + 2P6 + 3S2 +3P6 = 22

electron configuration for fluorine?

1s2 2s2 2p5

electron dot notation for silicon?

Silicon has 4 valence electrons so it would be Si with 4 dots around it on north south east and west.

maximum number of electrons in a orbital

2

purpose of electron dot notation

easy way to write electron configurations

Aufbau principle

theory that electrons must fill the lowest available energy sublevel before any ca be placed in higher energy sublevels.

Hunds rule

Electrons will occupy orbitals of the same energy one at a time, with parallel spins before any orbital gets a second electron

What is the ground state of an atom?

The lowest energy level

Valence electrons

The electrons in the outermost energy level that are important in bonding

What did Mendeleev arrange his periodic table by?

Atomic Mass

Who used x-rays to determine the atomic number of elements?

henry mosely

the pattern of atomic radius as u move down the groups?

They increase

pattern of atomic radius as u move across a period?

it decreases

T/F atoms are larger than ions

True

T/F Alkali metals are highly reactive

True

most common transitions metals

• Iron

• copper

• Nickel

• Chromium

• Manganese

• zinc

• Titanium

Where are the transition metals found?

D - block

Where are inner transition metals found?

F-block

what metal is liquid at room temp

Mercury

You measure the mass of a product in a chemical reaction to be 3.54 g. Theoretical

calculations predict that you should have obtained 3.65 g. What is the percent error?

Percent error = experimental - theoretical / theoretical (100)

3.54 - 3.65 / 3.65 (100) = 3.0137%

If you are not pursuing a career in chemistry, how can this course still prove useful? Describe the process of scientific inquiry that chemists and other scientists follow. What is God’s first commandment in Scripture, and what does it have to do with chemistry?

• make an observation

• ask questions

• form a hypothesis

• design and perform an experiment

• collect data / analize it

• make conclusion

these are all steps that even if you are not doing chem are importent steps and guide lines to follow in order to efficently problem solve. It is also usefull to the fact that these steps allow a person to come to conclusions about the truth as the first commandment with is you shall have no other gods before me these steps allow us to come come to conclusions and see the proof that god is real and put him in the proper authority.

Your teacher provides you with five samples of different elements that are not labeled and asks you to identify the group that they belong to. Design an experiment to determine which group they belong to. List at least three properties that you would test for and explain why you tested for it.

first test electron conductivity ( it would most likely be a metal ), then test reactivity to water and acid, and then lastly test its malleability ( likely also a metal )

difference between temp, thermal energy and heat

temp = a measure of the average kinetic energy of the particles in a substance.

Thermal energy = total energy of all the particles in a substance due to their motion and arrangement.

heat

is the transfer of thermal energy from a warmer object to a cooler object because of a temp difference.

You measure the mass of a product in a chemical reaction to be 5.43g. Theoretical

calculations predict that you should have obtained 4.63g. What is the percent error?

Write what you know.

Value observed = 5.43 g

Value expected = 4.63 g

% uncertainty = ?

Write the formula and solve for the unknown.

%error = (value observed − value expected __________________ value expected)100%

% error (5.43 - 4.63) / 4.63 (100) = 17.28%