Science unit 2 Chemistry

Question 1

What is an atom?

Answer 1

Atom: Represents the smallest possible particle of any element

Question 2

What is a element?

Answer 2

Element: A substance that cannot be reduced to any simpler substance by ordinary chemical

Question 3

What is a Molecule

Answer 3

Molecule: A chemical combination of more then one atom

Question 4

What is a Molecule and give an example

Answer 4

Chemical Compound: A molecule consisting of more then one type of atom (Ex: Water is made up of more then one element H2O)

Question 5

What is a Mixture?

Answer 5

Mixture: A bonding of Elements to make a substance, it can be mechanically separated.

Question 6

What 3 particles make up an atom?
Where are they located?
what charge do they have?

Answer 6

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

Question 7

What does the atomic number represent?

Answer 7

Atomic Number: is the number of protons in an atom

Question 8

What doe the atomic mass represent?

Answer 8

Atomic Mass: is the number of protons and Neutrons in an atom

Question 9

What is equal in a electrically balanced atom?

Answer 9

In an electrically balanced atom electrons and protons are equal

Question 10

What are some physical qualities about pure water?
what states can water be observed in?

Answer 10

Water is flavorless, odorless, and colorless, it can be observed as a liquid, gas, and solid

Question 11

What happens to water when it is heated and what happens when its cooled?

Answer 11

Water expands when heated or cooled

Question 12

at what tempeture is water most dense?

Answer 12

Water is most dense at 4 degrees C and expands when heated or cooled from that point

Question 13

At what temperature does water freeze and boil at?

Answer 13

Water freezes at 0 Degrees C and Boils at 100 degrees C

Question 14

• 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?

Answer 14

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

Question 15

What is the First Law of thermodynamics:

Answer 15

First Law of thermodynamics: Energy cannot be created or destroyed, only transformed from one form to another

Question 16

What is the Second Law of thermodynamics:

Answer 16

Second Law of thermodynamics: Heat energy may only flow from a body at a higher temperature to one with a lower temperature

Question 17

What is Enthalpy

Answer 17

Enthalpy is the name given to the amount of heat contained in a body (Measured in joules, calories, BTU and more)

Question 18

What does BTU stand for and what is it?

Answer 18

BTU: (British Thermal Units) is equal to the amount of heat energy required to rase the temperature of 1lb of water 1 degrees F

Question 19

What is temperature and what 4 ways is it measured

Answer 19

Temperature: the intensity of heat energy (measured in: C, F, R, or K)

Question 20

what are Absolute temperatures?
Which Absolute tempters corresponds to F and which to C?

Answer 20

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

Question 21

What is Absolute zero in C and F?
What 2 things happens at absolute zero

Answer 21

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

Question 22

What is specific heat?

Answer 22

Specific Heat: The amount of heat needed raise the temperature of a unit-mass of a substance by one degree

Question 23

What is sensible heat?

Answer 23

Sensible Heat: The kind of heat required to change the temperature of a substance

Question 24

What is Latent heat?

Answer 24

Latent Heat: The kind of heat required to change the state of a substance

Question 25

describe what happens in a Ionic Bond

Answer 25

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

Question 26

What charges and what are they?
- Ions
- Anions
- Cations
In a solution what must be equal?

Answer 26

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

Question 27

What is a solution and give an example

Answer 27

Solution: One substance is mixed homogeneously with another (Ex: Salt water)

Question 28

What is pH and what do the different ends of the scale mean?

Answer 28

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.

Question 29

How do you Dilute a strong base or acid?

Answer 29

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.

Question 30

What is a suspension and give an example

Answer 30

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)

Question 31

what is a covalent bond, how does it difffer from a ionic bond.
give an example

Answer 31

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

Question 32

What cation particles cause hard water (Name 2)
what deficiencys can hard water cause?

Answer 32

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