Chem Chapter 1 & 2

Combustion =

Burning

All matter is composed of tiny particles called atoms

Atomic Theory

Steps in the Scientific Method

1. Question/Problem

2. Hypothesis

3. Experiment

4. Analysis / Re-experiment

5. Conclusion

Define observation

A measurement of an aspect of nature

Define hypothesis

A tentative explanation or interpretation of observations.

T or F: A good hypothesis should not be falsifiable (logically be proven wrong by an observation or experiment)

False. A good hypothesis should be falsifiable

Define experiments

A controlled observation to prove of disprove hypotheses

What is a scientific law

A statement that summarizes past observations and predicts future ones

What is a theory

A proposed explanation for observations and laws

Law of Conservation

In a chemical reaction, matter is neither created nor destroyed

Define chemistry

The science that examines the connections between properties of matter and the particles that compose matter

Standard, agreed on quantity by which other quantities are measured.

Unit

To write in scientific notation, if an exponent is positive, then we move the decimal point to the _______

Left

To write in scientific notation, if an exponent is negative, then we move the decimal point to the _______

Right

How to write in scientific notation

First find a number between 1 and 10, and then count the decimal points.

How are numbers typically written when stating data?

Every digit is certain, except the last.

Rules for significant digits

1. All nonzero digits are sig (1.5)

2. Interior zeros are sig (zeros between two numbers) (1.06)

3. Trailing zeros that fall after the decimal point are sig (1.00)

4. Trailing zeros that fall before the decimal point (10.00)

T or F: Leading zeros (zeros to the left of the first nonzero number) are significant.

False. Leading zeros (zeros to the left of the first nonzero number) are not significant as they only serve to locate the decimal point

In multiplication or division, the result carries the same number of significant figures as the factor with the _______ significant figures.

Least

In addition or subtraction, the result carries the same number of decimal places as the quantity with the _______ ___________.

fewest decimal places

T or F: Addition and Subtraction answers can have a different number of sig digs than the initial quantity

True

Unit of Measurement

Meters

Use:

Symbol =

Use: Length

Symbol = m

Unit of Measurement

Kilogram

Use:

Symbol =

Use: Mass

Symbol = kg

Unit of Measurement

Seconds

Use:

Symbol =

Use: Time

Symbol = s

Unit of Measurement

Kelvin

Use:

Symbol =

Use: Temp

Symbol = K

Unit of Measurement

Gram

Use:

Symbol =

Use: Weight

Symbol = g

Tera

Meaning:

Multiplier:

Symbol:

Meaning: Trillion

Multiplier: 10 to the 12th

Symbol: T

Giga

Meaning:

Multiplier:

Symbol:

Meaning: Billion

Multiplier: 10 to the 9th

Symbol: G

Mega

Meaning:

Multiplier:

Symbol:

Meaning: Million

Multiplier: 10 to the 6th

Symbol: M

Kilo

Meaning:

Multiplier:

Symbol:

Meaning: Thousand

Multiplier: 10 to the 3rd

Symbol: k

Hecto

Meaning:

Multiplier:

Symbol:

Meaning: Hundred

Multiplier: 10 to the 2nd

Symbol: h

Deca

Meaning:

Multiplier:

Symbol:

Meaning: Ten

Multiplier: 10 to the 1st

Symbol: da

Deci

Meaning:

Multiplier:

Symbol:

Meaning: Tenth

Multiplier: 10 to the -1st

Symbol: d

Centi

Meaning:

Multiplier:

Symbol:

Meaning: Hundredth

Multiplier: 10 to the -2nd

Symbol: d

Milli

Meaning:

Multiplier:

Symbol:

Meaning: Thousandth

Multiplier: 10 to the -3rd

Symbol: m

Micro

Meaning:

Multiplier:

Symbol:

Meaning: Millionth

Multiplier: 10 to the -6th

Symbol: µ

Nano

Meaning:

Multiplier:

Symbol:

Meaning: Billionth

Multiplier: 10 to the -9th

Symbol: n

Pico

Meaning:

Multiplier:

Symbol:

Meaning: Trillionth

Multiplier: 10 to the -12th

Symbol: n

Femto

Meaning:

Multiplier:

Symbol:

Meaning: Quadrillionth

Multiplier: 10 to the -15th

Symbol: f

What happens when a unit of length is cubed?

It becomes a unit of volume

In calculations involving multiple steps, the step ____________ is done first, which also determines what about the answer?

inside the parentheses; that answer determines how many sig digs the answer should have