Quarter 2 Fall Semester Review

Front

A sample of 5.11 x 10^23 atoms of lithium is equal to _____ moles Li.

Back

0.849 moles Li

Front

Identify the element in Period 5 that has 1 valence electron.

Back

Rubidium (Rb)

Front

A sample 48.86 g of cobalt contains how many moles of cobalt?

Back

0.8291 mol Co

Front

A 10.0 g sample of magnesium reacts with oxygen to form 16.6 g of magnesium oxide. How many grams of oxygen reacted?

Back

6.6 g

Front

The molar mass of iron is _____ g/mol.

Back

55.85 g/mol

Front

What is the formula to calculate moles from grams?

Back

Moles = Mass (g) / Molar Mass (g/mol)

Front

What is the definition of molar mass?

Back

The mass of one mole of a substance, typically expressed in grams per mole (g/mol).

Front

How do you determine the number of valence electrons in an element?

Back

By looking at its group number in the periodic table.

Front

What is the law of conservation of mass?

Back

In a chemical reaction, mass is neither created nor destroyed.

Front

What is the significance of the periodic table in chemistry?

Back

It organizes elements based on their atomic number, electron configuration, and recurring chemical properties.