Untitled Flashcards Set
Atoms
What are the three subatomic particles?
Protons, neutrons, and electrons
What are the subatomic particles charges?
Protons- positive
Neutrons- neutral
Electrons- negative
How do you calculate the mass of an atom?
Protons + neutrons
Where are each of the subatomic particles located?
Protons and neutrons- in the nucleus
Electrons- surrounding the nucleus
What is the mass of a proton?
1 atomic mass unit (1 amu)
What is the mass of a neutron?
1 atomic mass unit (1 amu)
Elements & The Periodic Table
What is the overall charge of an element?
Neutral
How do you find the number of protons and electrons in an atom?
The atomic number of an element is the number of protons.
The number of electrons is equal to the number of protons.
How do you find the number of neutrons in an atom?
Atomic mass- protons = neutrons
What are valence electrons? Why are they important?
Valence electrons are the electrons farthest from the nucleus. They are important because they are responsible for bonding between atoms.
Calculate the number of protons, neutrons, electrons, and valence electrons for the following elements:
How do you know the number of electron shells an element has?
The period it is in is equal to the number of electron shells an element has.
How do you know the number of valence electrons an element has?
The group/family an element is in tells you how many valence electrons it has.
Why is Helium in group 18 if it doesn’t have 8 valence electrons?
Helium has a full valence shell just like all the other elements in group 18, even though Helium only has two while the rest have eight.
How many electrons can the second and third shells hold?
8
Draw a Bohr model and a Lewis dot structure for each of the following elements:
Why do we draw Bohr models?
To visualize the subatomic particles in an atom.
Why do we draw Lewis dot diagrams?
For a simpler view of an atom, so we can focus on the valence electrons only.
For each of the following families, write the group number, the members of the family, and 3 properties of the family.
Alkali metals
Group 1- Li, Na, K, Rb, Cs, Fr
Highly reactive, soft, not found in nature, low density
Alkaline earth metals
Group 2- Be, Mg, Ca, Sr, Ba, Ra
Good conductors, silver, rarely found in nature, reactivity increases as you move down the group
Halogens
Group 17- F, Cl, Br, I, At, Ts
Density is greater than air, poisonous, occur in combination with other elements, very reactive.
Noble Gasses
Group 18- He, Ne, Ar, Kr, Xe, Rn, Og
Full valence shell, do not combine with other elements, unreactive, found free in nature
Measurement
What is the base unit of:
Length- meter
Mass- gram
Volume- liter or cm3
Measure each line segment to the nearest millimeter.
Read the graduated cylinders and write the volume of each liquid below Include the correct units.
425 ml 4.8 ml 74 ml 146 ml
Calculating Density, Mass, & Volume
d=m/v m=d x v v=m/d
States of Matter
What are atoms?
The smallest unit of matter
What is matter?
Anything that has mass and takes up space
How do molecules act in cold temperatures?
They slow down and move closer together
How do molecules act in hot temperatures?
The speed up and spread further apart, moving past one another.
Put the three states of matter in order from fastest to slowest moving molecules.
Gas, liquid, solid
Which state of matter has a definite shape and volume?
Solid
Which state of matter has a definite volume but not a definite shape?
Liquid
Which state of matter does not have a definite volume or shape?
Gas
Draw the motion of the molecules for each state of matter
What happens to the molecules of a liquid when it freezes into a solid?
They slow down and move closer together, into a defined shape
What happens to the molecules of a solid when it melts into a liquid?
The molecules speed up and start moving past one another. The substance takes the shape of its container.
What happens to the molecules of a liquid when it evaporates into a gas?
The molecules move even faster, moving past each other and bumping into each other. The atoms take up as much space as possible.
What happens to the molecules of a gas when they condense into a liquid?
The molecules slow down and move closer together into a defined volume. They take the shape of their container.
Physical & Chemical Properties
Define the following terms:
Physical Properties- A characteristic of a substance that can be observed without changing it into a new substance.
Chemical Properties- A characteristic of a substance that describes its ability to change into a different substance.
Luster- The shininess of an object
Viscosity- How fast or slow a liquid flows
Malleability- the ability to pound a material into different shapes
Taste- The flavor of a substance
Odor- The smell of a substance
Texture- The roughness or smoothness of an object
Conductivity- The ability of a substance to transfer energy
Density- The measurement of how much mass of a substance is contained in a given volume.
Boiling Point- The point at which a liquid turns into a gas
Melting/Freezing Point- The point at which a liquid turns to a solid (freezing) or a solid turns to a liquid (melting)
Tarnish- A substances reaction to oxygen, blackish color
Solubility- The ability of a substance to dissolve
Rust- Ability of a substance to react to oxygen, reddish color
Magnetism- The ability of substances to attract or repel one another
Thermal Conductivity- The ability of a substance to transfer heat
pH- the acidity of a substance
Categorize the above terms as physical or chemical properties.
Define the following terms
Evaporation- Liquid to gas
Condensation- Gas to liquid
Melting- Solid to liquid
Freezing- Liquid to solid
Deposition- Gas to solid
Sublimation- Solid to gas