19 and 20 please

QUESTION TO Which of the following contains different types of atoms? An iron nail A sample of oxygen gas A piece of copper wire Sugar QUESTION 19 Based on periodic trends, a potassium atom should have a higher lonization than a bromine atom, True O False QUESTION 20 Modern atomic theory states that atoms have a structure much like a mini-solar system in that a positively charged nucleus is circled at various distances by small negatively charged electrons in specific orbits. This theory lead to descriptions of atoms using electron configurations and energy level diagrams. This conceptual structure of atoms was first proposed by the scientists in the (Fill in the blanks) Joseph Thomson and Max Planck; early 27th century O James Maxwell and Lord Kelvin; early 19th century O Stanislao Cannizzaro and William Rankine; early 18th century O Ernest Rutherford and Neils Bohr, early 20th century