Science Final Flashcards
What causes the glow of a neon light?
The electrons moving from a higher to lower energy level
If an unknown substance CANNOT be broken down into simpler substances, it is probably an ______.
Element
What did JJ Thomson’s experiments provided evidence for?
That an atom contains negativity charged particles
Which sublimation particle has a negative charge?
Electron
The Temp. and volume in a closed container of gas remain constant. If the number of particles of gas increased, what will happen to the gas pressure?
It will increase
The phase change that is the reverse of condensation is _________.
Vaporization
Define malleable, and give a example of things that are malleable.
Able to hammer or press permanently out of a shape without cracking (Gold, silver, and aluminum)
What does Boyles law states
The volume of gas
You are about to open a container of soy milk but notice that there are instructions to “Shake well before serving” The soy milk is likely a ____.
Suspension
Flammibility is a materials ability to burn in the presence of what?
Oxygen
Matter that has a definite volume but no definite shape is a _____.
Liquid
If the volume of a cylinder is reduced from 4.0 to 2.0 the pressure of the gas goes from 100K to ___K.
200
What are the characteristics of a mixture?
Varying roperties
AQ substance has a melting point of 0C and a boiling point of 100C. The substance is most likely what?
Water
How can you tell if a physical change in a sample occurs?
Texture, color, temp., shape
How can you tell if a chemical change in a sample has occured?
Odder, precipitate, bubble formation, color, temp.
Which of the group one elements is most reactive most to least.
Francium, Cesium, Rubidium, sodium, lithium, hydrogen.
If you move a container from one container to another and its volume changes, the substance is a ____.
Gas
How do you find the number of neutrons in an atom?
Mass-Atomic number
List the halogens from most reactive to least reactive
Florine, chlorine, bromine, iodine
Give me some examples of a heterogeneous mixture
A jar of mixed nuts, fruit salad
in Niels Bohrs model of the atom, how do electrons move
In a pattern similar to planets orbiting the sun
Comparing the Valence electrons, what is the difference between group 1 elements and group 7 elements?
Group 1 has 1 electron and group 7 has 7 electrons
What is the result of a force distributed over an area?
Pressure
What did Democritus think matter was made?
atoms
What is the difference between an atom at ground state, and an atom in an excited state?
The ground state is at the lowest energy level and exited state is the highest energy level
The phase in which a substance changes from a liquid to a gas ____.
Vaporization
Who provided evidence for the existence of a nucleus in an atom?
Ernest Rutherford
According to John Dalton’s observation how do elements combine in an compound?
The ratio of their masses is always the same
What factors affect the pressure of an enclosed gas?
Volume, Temperature, and amount
Something that is malleable and conducts electricity is most likely made of what material?
A metal
Among the alkiali metals, the tendency to react with other substances does what within its group?
Increases from top to bottom within the group
Collisions of helium atoms and the walls of a closed container cause ___ _____.
Gas Pressure
What characteristics does a gas have?
They expand to fill containers and they are easily compressed
How was Bohrs atomic model similar to Rutherfords model?
It showed a nucleus in the center
What clues can you look for to identify if a chemical change has occurred
Production of gas, changing in color, and formation of precipitate
Describe John Daltons model of the atom?
A tiny solid sphere with a predictable mass
List the similarities of the following elements fluorine, chlorine, and iodie
They are all halogens
A substance that has high reactivity easily does what?
React
The tendency of an element to react chemically is closely related to what?
Valence electrons
A substance that is made up of only one kind of atom is a ____
Element
In anatomic model that includes a nucleus where is the positive charge located?
In the center of an atom
the number of protons in one atom of an element is the same as that elements _____.
atomic number
99% of all the matter that can be observed in the universe exists as ____.
Plasma
The column on the far left of the periodic table contains what metals?
More reactive Metals
Which statement accurately represents the arrangement of electrons in Bohrs atomic model (Circle one)
- electrons travel around the nucleus and fixed energy levels with energies that vary from level to level
How is the atomic mass of an element determined?
Take a weighted average of the masses of the isotopes present in nature
In a periodic table how does a set of properties repeat?
From row to row
The phase change in which a substance changes from a gas directly to a solid is _____.
Deposition
During what phase change does the arrangement of water molecules become more orderly?
Freezing
What is the standard on which the atomic mass unit is based on?
carbon-12 atom
As you move from left to right across a period, the number of valence electrons does what?
Increases
What method can be used to separate parts of a liquid mixture when the entire mixture can pass through a filter?
Distillation
The Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided?
Atom
Which element is found in nature only in compounds?
Sodium
Why is water considered a compound?
Cause it has two elements H2O
What is the law that states that the volume of a gas is directly proportional to its temperature in kelvin if the pressure and the number of particles is consistent
Charles Law
atoms of the most reactive elements tend to have how many Valence electrons?
One or seven electrons
What can you assume has happened if and electron moves to a higher energy level?
The electron has gained energy
How was the usefulness of Mendeleevs periodic table confirmed?
The discovery of elements with predicted properties
What type of change occurs when water changes from a solid to a liquid?
melting
From left to right across the row of the periodic table what increases by exactly one from element element
Atomic number
The phase change in which a substance changes from a solid to a liquid is _____.
Melting
Mixture can be classified as a solution suspension or colloid based on what
The size of its largest particles
If a material contains three elements joined in a fixed proportion it is a _____.
Compound
Which of the following group 7A elements is the most reactive? List for most reactive to least reactive
Fluoride, chlorine, bromine, iodine
What does the electron cloud model describe?
The most likely location of electrons and Atom
Mendeleev changed the non-chemical elements in a table cream to increasing what?
Mass
To keep them from reacting some highly reactive elements are starting what?
Argon
An alkali metal has one valence electron, while an alkaline earth metals has how many electrons?
Two
What physical properties of nylon and leather make them good materials to use for shoelaces?
Durability and flexibility
Figure 5–1 shows a portion of a blank periodic table identify the segments labeled A and B
A – Period. B- group
How can temperature be used to recognize a phase change
If the temperature does not change
What are the subatomic particles? What are their masses what charger do they have?
They are smaller than atoms. Protons- electrons- neutrons-
The phase change in which a substance changes from a solid to a gas or vapor without reading to liquid first is____.
sublimation
Which element is found in most of the compounds in your body except water
Carbon
Give examples of pure substances?
Water, oxygen, and carbon dioxide
