2. Atoms & Elements

How many elements are present in period 6 of the periodic table?

Which of the following statements correctly describes the first 30 elements of the periodic table?

Which properties of gallium was Mendeleev able to predict before its discovery?

Which three elements are the most abundant in Earth's crust?

Which of the following elements is found in period 3 of the periodic table?

Which one of the following elements is NOT among the eight most abundant elements in the Earth's crust?

Which element on the periodic table is commonly recognized as having properties of both metals and nonmetals?

Which of the following lists correctly identifies the top eight most abundant elements in Earth's crust by mass?

Which sections of the periodic table are excluded from the main group elements?

Which of the following elements is a main-group (representative) element?

Which of the following elements make up most of Earth's crust?

Which element is the only metalloid in period 3 of the periodic table?

Which of the following is a lanthanide element?

Which element was discovered by Marie and Pierre Curie?

Which element has a total of two occupied principal energy levels?