Chemistry 9 chapter 1 1st quiz

Basic unit of substance

• Atom

• Elements

• Molecules

• Compound

The atom as a hard, indivisible sphere.

• Dalton

• Thomson

• Rutherford

• Bohr

Who discovered electrons

• Dalton

• Rutherford

• Thomson

• Bohr

Rutherford introduced his perception that protons are situated in a tiny area at the center of the atom called the............

• Proton

• Electron

• Nucleus

• Atom

electrons rotate around the nucleus in various orbits with varying distances from the nucleus as is the case of planets rotating around the sun. Therefore, this model is called the.................

• Planet

• Planetary Astral model

• Thomson

• Rutherford

Each energy level has a distinctive number describing its energy, this number is called principal quantum number. An electron in the first energy level has a principal quantum number of I, while the electron in the second energy level has a principal quantum number of 2 and so forth. The farther from the nucleus the more the level of energy, for example first energy level is less than the second and so forth.

• Bohr

• Thomson

• Rutherford

• Dalton

Which energy level is the highest?

• First

• Second

• Third

• Fourth

This space is called the.............. , which can be best expressed as the electron cloud surrounding the nucleus.

• Electron

• Proton

• Orbital

• Atom

1- The atoms consists of a nucleus surrounded by electrons with varying levels of energy

2. Electrons rotate around the nucleus on a distance, ( according to the size of the atom ), in energy levels these levels are represented by numbers called principal quantum numbers , positive integers with the symbol ( n ) .

In addition to this, and as we have learned earlier, the nucleus at the center of the atom and consists of the protons and neutrons.

• Thomson

• Rutherford

• Modern atomic theory

• Dalton