Unit 2 Exam

Why did scientists accept the Mendeleev’s periodic table as a useful way to organize information about the elements?

• Mendeleev was a well-respected scientist.

• The table was demonstrated to have predictive value.

• There was no other way to organize the information, and so chemists used the table.

• The description of atomic structure was presented better in the table than in other tools.

Mendeleev noticed that properties of elements usually repeated at regular intervals when the elements were arranged in order of increasing

• atomic number.

• density.

• reactivity.

• atomic mass.

The person whose work led to a periodic table based on increasing atomic number was

• Moseley.

• Mendeleev.

• Rutherford.

• Cannizzaro.

Which of the following is a false statement regarding Newlands' Law of Octaves arrangement of the elements.

• identified many similarities amongst the elements, but also required similarities where none existed

• did not leave spaces for elements as yet undiscovered

• forerunner to the notion of periods

• predicted that there were 3 unknown elements between aluminum and gold

Sodium (Na) metal reacts violently with water to form hydrogen gas. Which element has a similar reaction when combined with water?

• gold (Au)

• lithium (Li)

• silicon (Si)

• zinc (Zn)

Based on the arrangement of elements in the periodic table, what can you predict about the properties of a synthetic element that has an atomic number of 118?

• Element number 118 would be very reactive and have metallic properties.

• Element number 118 would be a metallic element that readily forms salts with metallic elements.

• Element number 118 would be a nonmetallic gas whose atoms are unlikely to react with other atoms.

• Element number 118 would be a metalloid with some properties of both metals and nonmetals.

In which set of elements would all members be expected to have very similar chemical properties?

• O, S, Se

• N, O, F

• Na, Mg, K

• S, Se, Si

Ernest Rutherford performed an experiment in which he shot alpha particles through a thin layer of gold foil. He predicted that the alpha particles would travel straight through the gold atoms.

However, Rutherford observed that although most of the alpha particles passed straight through the foil, a few alpha particles were deflected.

Which of the following statements about the atom did Rutherford’s experiment support?

• An atom contains protons, neutrons, and electrons.

• An atom’s nucleus is small and has a positive charge.

• Electrons follow a predictable path around the nucleus.

• Different isotopes of an element have different masses.

Which of the following statements is not an idea from Dalton's Atomic Theory?

• An element is composed of extremely small indivisible particles called atoms.

• All atoms of a given element have identical properties which differ from those of all other elements.

• Atoms can only be transformed into atoms of another element by nuclear reactions.

• Compounds are formed when atoms of different elements combine with each other in small whole-number ratios. The relative numbers and kind of atoms are constant in a given compound.

Which idea of John Dalton is no longer considered part of the modern view of atoms?

• Atoms are extremely small.

• Atoms of the same element have identical masses.

• Atoms combine in simple whole number ratios to form compounds.

• Atoms of different elements can combine in different ratios to form different compounds.