Q: Which equation correctly relates the number of neutrons in an atom to its mass number and atomic number?

$$\text{Number of neutrons} = \text{mass number} - \text{atomic number}$$

Question 1

Which experiment led to the discovery of the electron and what was the key observation?

Accepted Answer

Thomson's cathode ray tube experiment; cathode rays were deflected by electric and magnetic fields

Question 2

Which of the following statements best describes the difference between isotopes of an element?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons

Question 3

In Rutherford's gold foil experiment, what unexpected result led to the nuclear model of the atom?

Accepted Answer

Alpha particles bounced back, indicating a dense, positively charged nucleus

Question 4

Which type of radiation has the greatest penetrating power?

Accepted Answer

$$\gamma$$ radiation

Question 5

Given the isotope notation $$^{14}_{6}\mathrm{C}$$, how many neutrons does this isotope of carbon have?

Accepted Answer

8

Question 6

Which scientist is credited with discovering X-rays, and what was the significance of this discovery?

Accepted Answer

Wilhelm Conrad Röntgen; it provided evidence for the existence of subatomic particles

Question 7

Which equation correctly relates the number of neutrons in an atom to its mass number and atomic number?

Accepted Answer

$$	ext{Number of neutrons} = 	ext{mass number} - 	ext{atomic number}$$

Question 8

Which of the following best explains why the plum pudding model was replaced by the nuclear model?

Accepted Answer

The nuclear model explained the deflection of alpha particles observed in Rutherford's experiment

Question 9

If an atom has 17 protons, 18 neutrons, and 17 electrons, what is its atomic number and mass number?

Accepted Answer

Atomic number: 17, Mass number: 35

Question 10

Which of the following is a correct statement about the Bohr model of the atom?

Accepted Answer

Electrons are found in fixed orbits around the nucleus and can only occupy certain energy levels

Question 11

Which type of radiation consists of high-energy electrons?

Accepted Answer

$$\beta$$ radiation

Question 12

A sample contains two isotopes of neon: $$^{20}\mathrm{Ne} (90.5$$%) and $$^{22}\mathrm{Ne} (9.5$$%). What is the average atomic mass of neon in this sample?

Accepted Answer

$$20.19\ \mathrm{amu}$$

Question 13

Which subatomic particle determines the identity of an element?

Accepted Answer

Proton

Question 14

Which of the following best describes the electromagnetic spectrum?

Accepted Answer

It includes all types of electromagnetic radiation, from radio waves to gamma rays

Question 15

Which scientist's experiment measured the charge of the electron and helped determine its mass?

Accepted Answer

Robert Millikan

Question 16

What is the charge and mass of a proton?

Accepted Answer

Charge: $$+1$$, Mass: $$1\ \mathrm{amu}$$

Question 17

Which of the following best explains why atoms are electrically neutral?

Accepted Answer

Atoms have equal numbers of protons and electrons

Question 18

Which type of spectrum is produced when white light passes through a prism?

Accepted Answer

Continuous spectrum

Question 19

Which of the following statements about ions is correct?

Accepted Answer

An ion is an atom or molecule with a net electric charge due to loss or gain of electrons

Question 20

Which of the following best describes the difference between $$\alpha$$, $$\beta$$, and $$\gamma$$ radiation?

Accepted Answer

$$\alpha is a $$helium nucleus, $$\beta is a $$high-energy electron, $$\gamma is a $$high-energy photon

Atomic Structure: Historical Development, Subatomic Particles, and Electron Arrangement

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