Key Concepts 4.1: The United States began to develop a modern democracy and celebrated a new national culture, while Americans sought to define the nation’s democratic ideals and change their society and institutions to match them. Answers for Period (4) crossword clue, 4 letters. Search for crossword clues found in the Daily Celebrity, NY Times, Daily Mirror, Telegraph and major publications. The fourth period contains 18 elements beginning with potassium and ending with krypton – one element for each of the eighteen groups. It sees the first appearance of d-block (which includes transition metals) in the table. Interactive periodic table showing names, electrons, and oxidation states. Visualize trends, 3D orbitals, isotopes, and mix compounds. Fully descriptive writeups. Period 4 is the first row where transition metals appear. It runs from potassium to krypton and includes iron, copper, zinc and nickel - the metals that power everything from kitchen knives to electric grids. Continue your AP U.S. History test prep with APUSH Period 4 study notes from Barron’s. See a timeline of what happens in Period 4 of APUSH and review key exam topics you should know for the APUSH exam. Fiveable's AP US History Unit 4 review covers 14 topics, with guided practice questions for the unit. Sets up the three key concepts for 1800-1848: the development of participatory democracy, the emergence of a national culture, and the expansion of U.S. territory and its consequences for slavery. AP U.S. History Practice Test (Period 4: 1800-1848). This test contains 10 AP U.S. history practice questions with detailed explanations, to be completed in 10 minutes. Period 4 was marked by major changes in politics, economics, and society that reshaped the young nation. In this lesson, you’ll learn how to explain the causes and effects of key developments between 1800 and 1848. This era was marked by a period of nationalism, optimism, and overall good will. One new aspect of the government was that only one political party reigned.