Unit 2: Ch 2 & Ch 3 (Sig Fig, Dim.Anay, Isotopes, Moles)

Front

What are significant figures?

Back

Significant figures are the digits in a number that contribute to its precision, including all non-zero digits, any zeros between significant digits, and trailing zeros in the decimal portion.

Front

How do you determine the number of significant figures in a measurement?

Back

Count all non-zero digits, any zeros between them, and trailing zeros in a decimal number. Leading zeros are not counted.

Front

What is dimensional analysis?

Back

Dimensional analysis is a mathematical technique used to convert units from one system to another, ensuring that the final answer is in the desired units.

Front

How do you perform dimensional analysis?

Back

Identify the given quantity and its units, determine the conversion factors needed, and multiply the quantity by the conversion factors to cancel out the unwanted units.

Front

What is an isotope?

Back

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons, resulting in different mass numbers.

Front

How do you calculate the number of moles from particles?

Back

Use Avogadro's number (6.022 x 10^23) to convert particles to moles: Moles = Number of particles / Avogadro's number.

Front

What is the molar mass of a substance?

Back

The molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol), and is numerically equal to the substance's atomic or molecular weight.

Front

How do you calculate the mass of a substance from moles?

Back

Mass = Moles x Molar Mass.

Front

What is the significance of protons in an atom?

Back

Protons determine the identity of an element and its position on the periodic table, as well as its chemical properties.

Front

What does the mass number represent?

Back

The mass number is the total number of protons and neutrons in an atom's nucleus.