Chem final - Exam 1 ch E/1

Question 1

Law of conservation of mass

Answer 1

-Matter is neither created or destroyed

Question 2

Law of conservation of energy

Answer 2

-Energy cannot be created or destroyed

Question 3

Pure substances

Answer 3

-One type of particle or component
-Cannot be separated
-Chemically bonded
-Fixed ratio
-Lines connecting or same color

Question 4

Mixture

Answer 4

-2 or more proportions that can vary from one sample to another
-Not chemically bonded

Question 5

Heterogenous mixture

Answer 5

-Components vary from one region of the mixture to another
-Not even

Question 6

Homogenous mixture

Answer 6

-Same composition throughout
-Mixed evenly

Question 7

Element

Answer 7

-Pure substance made of one type of atom
-Periodic table

Question 8

Compound

Answer 8

-2 or more different elements chemically bonded
-Fixed ratio

Question 9

Atoms

Answer 9

-Smallest unit
-Periodic table

Question 10

Molecules

Answer 10

-2 or more atoms chemically bonded

Question 11

Precision

Answer 11

How consistently you can get the same results

Question 12

Accuracy

Answer 12

How close you are to the true result

Question 13

Addition/subtraction sig figs

Answer 13

-Use least amount of decimal places

Question 14

Multiplication/division sig figs

Answer 14

-Use least amount of sig figs

Question 15

Density equation

Answer 15

density = m/v

Question 16

to find mass in the densest equation

Answer 16

mass = d * v

Question 17

To find volume in the density equation

Answer 17

Volume = m/d

Question 18

Density of water at 25 c

Answer 18

1g/1mL

Question 19

Law of multiple proportions

Answer 19

-When elements combine to form different compounds the ratios of their masses can be expressed as whole numbers

Question 20

Law of definite proportions

Answer 20

-A given compound always contains the same proportions of elements
-2 H and 1 O is always water

Question 21

Atomic theory

Answer 21

-Each element is composed of tiny indestructible particles called atoms
-All same elements have same mass/same everything
-Atoms combine in whole number ratios
-Atoms of one element can only change the way they’re bound

Question 22

Isotope

Answer 22

-Same number of protons
-Diff number of neutrons

Question 23

How to find neutrons

Answer 23

Mass number - atomic number

Question 24

How to find mass number (top number on square)

Answer 24

-Protons + neutrons

Question 25

Atomic number (Bottom number on square)

Answer 25

-Protons
-Electrons

Question 26

Ion

Answer 26

-Electrons are gained or lost

Question 27

What defines what makes an atom an atom

Answer 27

-Protons

Question 28

Electron weight

Answer 28

1800x lighter