Law of Chemical Combinations, SFs, The Atomic Models

Question 1

this law states that the total mass of substances combined does not change and thus is conserved.

Answer 1

Law of Mass Conservation

Question 2

this law states that a chemical compound is always made up of the same elements in fixed masses.

Answer 2

Law of Definite Proportions

Question 3

this law state that when two elements are combined, their fixed masses can be expressed as a simple ratio.

Answer 3

Law Multiple Proportions

Question 4

All “___” digits are significant figures. (ex. 2345, 4SFs)

Answer 4

Non-zero

Question 5

“___” in the middle of “___” are significant figures. (ex.2.30005, 6SFs)

Answer 5

1. ) Zeroes

2. ) Non_zero

Question 6

“_____” are NOT significant figures. (ex. 0.00000023, 2SFs)

Answer 6

Leading Zeroes

Question 7

“____” are significant figures if there is a DECIMAL POINT. (ex. 50000.00, 6SFs or 5000, 1SFs)

Answer 7

Trailing Zeroes

Question 8

if a “____”, overline or UNDERLINE is present, it means it is the LAST significant figure of an ambigouous number.

Answer 8

vinculum

Question 9

is the closeness of the measures value to a target.

Answer 9

Accuracy

Question 10

is the closeness of the values to each other.

Answer 10

Precision

Question 11

Who made the Solid-Sphere Model in 1803? What did he proposed?

Answer 11

1. ) John Dalton

2. ) He proposed that atoms are indivisible

Question 12

Who made the Plum-Pudding Model in 1904? What did he doscovered?

Answer 12

1. ) Joseph John Thompson

2. ) He discovered the electrons which he called corpuscles

Question 13

Who made the Nuclear Model in 1911? What did he discovered?

Answer 13

1. ) Ernest Rutherford

2. ) He discovered that the positive charge is in the nucleus

Question 14

Who made the planetary Model in 1913? What did he proposed?

Answer 14

1. ) Neils Bohr

2. ) He proposed that electrons move in fixed orbits

Question 15

Who made the Quantum Model (1926-present)? What did he discover?

Answer 15

1. ) Erwin Schrodinger

2. ) He discovered that electrons move in an electron cloud.