Properties and Reactivity of Halogens

This video introduces Group 7 elements, known as halogens, which include fluorine, chlorine, bromine, iodine, and astatine. Each element's atomic structure, including protons, electrons, and neutrons, is discussed. The video explains the reactivity of halogens, noting that reactivity decreases with increasing atomic number. Physical properties such as state, color, melting, and boiling points are also covered. The video concludes with a brief summary and encourages viewers to engage with the content.

Which of the following elements is not a halogen?

• Iodine

• Oxygen

• Chlorine

• Fluorine

How many electrons are present in the outer shell of halogens?

• 5

• 8

• 6

• 7

What is the atomic number of chlorine?

• 35

• 17

• 53

• 9

Which halogen has an atomic mass of 127?

• Chlorine

• Bromine

• Fluorine

• Iodine

Why does reactivity decrease as the atomic number increases among halogens?

• More electrons make it more stable

• More protons make it less reactive

• Nucleus becomes unstable

• Electrons are further from the nucleus

Which halogen is the most reactive?

• Bromine

• Fluorine

• Chlorine

• Astatine

What is the state of bromine at room temperature?

• Plasma

• Gas

• Liquid

• Solid

Which halogen has a melting point of 114 degrees Celsius?

• Chlorine

• Fluorine

• Astatine

• Iodine

What color is chlorine gas?

• Greenish-yellow

• Dark gray

• Yellow

• Red-brown

Which halogen is a dark gray solid at room temperature?

• Astatine

• Fluorine

• Chlorine

• Iodine