0. Chemistry of life

Which element is most abundant in the human body?

• Carbon

• Hydrogen

• Oxygen

• Nitrogen

What percentage of the atmosphere is composed of nitrogen?

• 65%

• 21%

• 78%

• 3%

What is the charge of a proton?

• Neutral

• Positive

• Negative

• No charge

What is the smallest unit of matter that retains all chemical properties of an element?

• Molecule

• Atom

• Electron

• Neutron

What does the nucleus of an atom contain?

• Electrons and protons

• Neutrons and electrons

• Protons and neutrons

• Electrons only

What is the charge of a proton?

• +1

• 0

• -1

• +2

Where are electrons located in an atom?

• Nucleus

• Orbitals

• Protons

• Neutrons

Who created the periodic table?

• Newton

• Einstein

• Mendeleev

• Curie

What are isotopes?

• Atoms with the same number of protons but different numbers of neutrons

• Atoms with different numbers of protons and neutrons

• Atoms with the same number of neutrons but different numbers of protons

• Atoms with the same number of protons and neutrons

What describes the energy loss when an unstable atom's nucleus releases radiation?

• Nuclear fusion

• Radioactive decay

• Chemical reaction

• Nuclear fission