1) Distinguish between an element and an atom?

1. The term "atom" is utilized for sub microscopic particles in a sample. "Atoms" consist of "elements." The "element" is another term for the "elementary particle."

2. The term "element" is utilized for microscopic and macroscopic samples. The samples consist of "atoms." The "atom" is a sub microscopic particle in a sample.

3. "Element" and "atom"are convertible terms.

2) Distinguish between mass number and atomic number?

1. Atomic number is the total number of protons and neutrons in the nucleus. Mass number is the number of protons in the nucleus.

2. Atomic number is the number of protons in the nucleus. Mass number is the total number of protons and neutrons in the nucleus.

3. Atomic number is the number of neutrons in the nucleus. Mass number is the total number of protons and neutrons in the nucleus.

4. Atomic number is the number of protons in the nucleus. Mass number is the total number of neutrons in the nucleus.

3) What happens to the properties of elements as you go across any period of the periodic table?

1. Across any period, the properties of elements change gradually.

2. The properties of elements do not change as you go across any period of the periodic table.

3. Across any period, the properties of elements change without any definite dependence on position.

4) What is a practical application of the wave nature of an electron?

1. Spectroscope

2. Optical Microscope

3. Electron microscope

4. Scanning probe microscope

5) Which electrons are most responsible for the properties of an atom?

1. The electrons in the outermost shell of an atom.

2. The electrons in the innermost shell of an atom.

3. The electrons in the intermediate filled shells of an atom.

4. The electrons in every shell of an atom are equally responsible for the properities of an atom.