91Ó°ÊÓ

How does the arrangement of elements in the modern periodic table differ from that of Mendeleev's periodic table?

Write the elemental symbols for nitrogen, silicon, phosphorus, potassium, and gold.

List three properties of metals and two properties of nonmetals. Describe the behavior of metalloids relative to the behaviors of metals and nonmetals.

Explain why Rutherford expected all alpha particles to go through the gold foil undisturbed.

(a) The elements in group IA (1) are called (b) The elements in group IIA (2) are called (c) The elements in group VIIA(17) are called (d) The elements in group VIIIA (18) are called

Write the full atomic symbol for each isotope: (a) 8 protons, 9 neutrons (b) Atomic number 50 , mass number 119 (c) 12 neutrons, atomic number 11 (d) 28 protons, mass number 58 (e) 81 neutrons, symbol Ba

Complete the following statements: (a) The nucleus contains the charged particles in the atom. (b) The particles in the nucleus are the and (c) Almost all of the mass of an atom is contained in the (d) The two particles whose charges cancel to make an atom neutral are and

How do metals and nonmetals differ with regard to their tendency to gain or lose electrons? With their tendency to form cations or anions?

Calcium reacts with fluorine to form the compound \(\mathrm{CaF}_{2}\). In the reaction, each atom of one of the elements loses two electrons, and each atom of the other element gains one electron. (a) Atoms of which element gain electrons? (b) Atoms of which element lose electrons? (c) What is the charge on the atoms that gain one electron? (d) What is the charge on the atoms that lose two electrons? (e) Write the full atomic symbol, including charges, for each element. Give Ca 20 neutrons and F 10 neutrons.

Use the elements lithium, potassium, and sodium to explain what is meant by chemical periodicity.