Science Quiz

Which of the following best describes the role of neutrons in an atom?

• They determine the charge of the atom.

• They balance the number of protons and electrons.

• They add mass and help stabilize the nucleus.

• They orbit the nucleus with electrons.

Why did Dmitri Mendeleev’s periodic table gain widespread acceptance?

• It was the first table to include all elements.

• He predicted properties of elements not yet discovered.

• He grouped elements by color.

• He arranged elements alphabetically.

Which statement about the Law of Conservation of Mass is correct?

• It applies only to physical changes.

• It requires all reactions to be reversible.

• It ensures total mass remains constant in closed systems.

• It is not applicable to nuclear reactions.

Tags

NGSS.MS-PS1-5

Which of the following is NOT an example of a chemical change?

• Baking bread

• Dissolving sugar in water

• Burning a candle

• Rusting of iron

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What is the primary difference between isotopes of the same element?

• The number of protons

• The number of neutrons

• The number of electrons

• Their chemical properties

Which of the following trends increases as you move across a period in the periodic table?

• Atomic radius

• Electronegativity

• Metallic character

• Reactivity of metals

Tags

NGSS.HS-PS1-1

What type of bond is formed when electrons are shared equally between two atoms?

• Ionic bond

• Isotope bond

• Covalent bond

• Metallic bond

Which of the following is true about the reactivity of alkali metals?

• It decreases as you move down the group.

• It increases as you move down the group.

• It remains constant across the group.

• It depends on the number of neutrons in the nucleus.

What is the density of an object with a mass of 45g and a volume of 15cm?

• 3g/cm

• 15g/cm

• 30g/cm

• 1.5g/cm

What is the charge of an ion that has gained two electrons?

• +2

• -2