Science unit 2 Chemistry Flashcards
What is an atom?
Atom: Represents the smallest possible particle of any element
What is a element?
Element: A substance that cannot be reduced to any simpler substance by ordinary chemical
What is a Molecule
Molecule: A chemical combination of more then one atom
What is a Molecule and give an example
Chemical Compound: A molecule consisting of more then one type of atom (Ex: Water is made up of more then one element H2O)
What is a Mixture?
Mixture: A bonding of Elements to make a substance, it can be mechanically separated.
What 3 particles make up an atom?
Where are they located?
what charge do they have?
Atoms can be broken down into 3 particles
Protons: Positive charge, in the nucleus of the atom
Neutrons: No charge, in the nucleus of the atom
Electrons: Negative charge, outside the nucleus
What does the atomic number represent?
Atomic Number: is the number of protons in an atom
What doe the atomic mass represent?
Atomic Mass: is the number of protons and Neutrons in an atom
What is equal in a electrically balanced atom?
In an electrically balanced atom electrons and protons are equal
What are some physical qualities about pure water?
what states can water be observed in?
Water is flavorless, odorless, and colorless, it can be observed as a liquid, gas, and solid
What happens to water when it is heated and what happens when its cooled?
Water expands when heated or cooled
at what tempeture is water most dense?
Water is most dense at 4 degrees C and expands when heated or cooled from that point
At what temperature does water freeze and boil at?
Water freezes at 0 Degrees C and Boils at 100 degrees C
- What is Heat?
- How can it be identified? (2 ways)
- Is heat able to move from one body to another?
- are we able to turn heat into other forms of energy?
Heat: Is a form of energy that can be identified by a change of temperature or a change in state. Heat can move from one body to another and can change to and from other forms of energy
What is the First Law of thermodynamics:
First Law of thermodynamics: Energy cannot be created or destroyed, only transformed from one form to another
What is the Second Law of thermodynamics:
Second Law of thermodynamics: Heat energy may only flow from a body at a higher temperature to one with a lower temperature
What is Enthalpy
Enthalpy is the name given to the amount of heat contained in a body (Measured in joules, calories, BTU and more)
What does BTU stand for and what is it?
BTU: (British Thermal Units) is equal to the amount of heat energy required to rase the temperature of 1lb of water 1 degrees F
What is temperature and what 4 ways is it measured
Temperature: the intensity of heat energy (measured in: C, F, R, or K)
what are Absolute temperatures?
Which Absolute tempters corresponds to F and which to C?
Absolute temperatures: These temperatures begin at absolute zero which means they start at 0 and are only positive after that
Rankine: R= F + 460
Kelvin: K= C + 273
What is Absolute zero in C and F?
What 2 things happens at absolute zero
Absolute Zero: is -273.16 Degrees C or -460 Degrees F. there is no more heat energy at absolute zero and all molecular motion stops
What is specific heat?
Specific Heat: The amount of heat needed raise the temperature of a unit-mass of a substance by one degree
What is sensible heat?
Sensible Heat: The kind of heat required to change the temperature of a substance
What is Latent heat?
Latent Heat: The kind of heat required to change the state of a substance
describe what happens in a Ionic Bond
Ionic Bond: are Formed when one atom allows electrons to pass to another atom. The atom giving up the electron takes a positive charge well the other takes a negative one
What charges and what are they?
- Ions
- Anions
- Cations
In a solution what must be equal?
Ion: A charged atom (or group)
Anion: A negatively charged atom (or group)
Cation: A positively charged atom (or group)
Positive charges must equal the negative charges in a solution
What is a solution and give an example
Solution: One substance is mixed homogeneously with another (Ex: Salt water)
What is pH and what do the different ends of the scale mean?
pH: is an expression of the degree of acidity or basicity of a solution. It ranges from 0-14, 0 being the strongest acid and 14 being the strongest base. 7 is neutral.
How do you Dilute a strong base or acid?
Neutralize: you can dilute/neutralize a strong base or acid by using its counterpart. Or large quantities of water which is neutral and will at least dilute it.
What is a suspension and give an example
Suspension: is another form of ionic bond, it is much easier to separate then a Solution as they are not homogeneously joined (Ex: sand in water)
what is a covalent bond, how does it difffer from a ionic bond.
give an example
Covalent Bond: formed between atoms when they share electrons. This is a much stronger bond than a Ionic bond
Example of this is H2O (Water), 2 Hydrogen atoms are covalently bonded to one oxygen atom
What cation particles cause hard water (Name 2)
what deficiencys can hard water cause?
Water Hardness: is usually produced by having cation particles. In particular these would include Ca (Calcium) and Mg (Magnesium)
Hard water can:
-Clog pipes
-Bad taste
-Increase soup use
-Higher heating cost
-Film on tubs
-Leave a feeling of a coating on skin
