Science MCQs

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Total Questions

2100

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Question 1681 Easy

Which isotope is used to treat cancer?

Carbon-14

Cobalt-60

Nitrogen-15

Oxygen-16

Question 1682 Easy

Which isotope is used to date ancient plants?

Carbon-14

Sodium-24

Iodine-131

Phosphorus-32

Question 1683 Easy

What is a molecule?

A charged atom

The smallest particle that can exist independently

A subatomic particle

An isotope

Question 1684 Easy

A molecule of oxygen gas is?

H2O

Question 1685 Easy

The chemical formula for water is?

H2O

H2O2

HO2

Question 1686 Easy

What does the subscript in a chemical formula indicate?

Charge of the atom

Number of atoms

Type of element

Valency

Question 1687 Easy

In CO₂ the subscript 2 indicates?

2 carbon atoms

2 oxygen atoms

2 molecules

2 bonds

Question 1688 Easy

What is the chemical formula of sodium chloride?

NaCl

NaCl2

Na2Cl

ClNa

Question 1689 Easy

The crisscross method is used to write?

Atomic numbers

Chemical formulae

Isotopes

Electron configurations

Question 1690 Easy

What is the formula for magnesium chloride?

MgCl

MgCl2

Mg2Cl

Cl2Mg

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