Chemistry level 10 Quiz

What subatomic particle was discovered first, leading to a change in the model of the atom?

• Proton

• Neutron

• Electron

• Nucleus

Which of the following particles is not found in the nucleus of an atom?

• Proton

• Neutron

• Electron

• Nucleon

What is the process called when an unstable atom changes into a stable atom by emitting radiation?

• Nuclear fusion

• Nuclear fission

• Radioactive decay

• Ionisation

Which of the following best describes the organisation of elements in the periodic table?

• By increasing atomic mass

• By increasing atomic number

• By alphabetical order

• By date of discovery

What is the significance of periods in the periodic table?

• They indicate the number of valence electrons.

• They indicate the number of electron shells.

• They indicate the atomic mass.

• They indicate the reactivity of elements.

Which of the following is a trend observed across a period in the periodic table?

• Atomic size increases

• Atomic size decreases

• Reactivity increases

• Metallic character increases

Which of the following elements is a non-metal?

• Sodium

• Aluminium

• Chlorine

• Iron

What is the primary factor that determines the chemical properties of an element?

• Number of protons

• Number of neutrons

• Number of electrons

• Atomic mass

Which of the following elements is most reactive?

• Helium

• Fluorine

• Neon

• Argon

What is the term for the horizontal rows in the periodic table?

• Groups

• Periods

• Families

• Series