Basic Science Concepts for Grade 9

What is the basic unit of matter?

• cell

• electron

• molecule

• atom

Who proposed the atomic theory?

• Erwin Schrödinger

• Niels Bohr

• Albert Einstein

• John Dalton

What is the charge of a proton?

• +2 elementary charge

• -1 elementary charge

• +1 elementary charge

• 0 elementary charge

What is the formula for calculating the number of neutrons in an atom?

• Neutrons = Mass Number - Atomic Number

• Neutrons = Mass Number * Atomic Number

• Neutrons = Atomic Number - Mass Number

• Neutrons = Atomic Number + Mass Number

What does the chemical formula H2O represent?

• Hydrogen Peroxide

• Carbon Dioxide

• Water

• Ozone

How do you balance the equation: H2 + O2 → H2O?

• 2 H2 + O2 → 2 H2O

• H2 + O2 → H2O

• H2 + 2 O2 → H2O

• 2 H2 + 2 O2 → 2 H2O

What is the purpose of a chemical symbol?

• To represent elements in a standardized way.

• To represent the color of an element.

• To indicate the atomic mass of an element.

• To show the chemical reactions of compounds.

What is the difference between an element and a compound?

• An element can be made of multiple types of atoms, while a compound is made of a single type of atom.

• Elements can be broken down into simpler substances, whereas compounds cannot.

• A compound is a pure substance, while an element is a mixture of different substances.

• An element consists of one type of atom, while a compound consists of two or more different types of atoms chemically bonded.

What are the main functions of the nervous system?

• Vision processing, sound perception, and taste sensation.

• Respiratory control, digestion, and blood circulation.

• The main functions of the nervous system are sensory input, integration, and motor output.

• Emotional regulation, memory storage, and hormone production.

What part of the nervous system controls voluntary actions?

• Peripheral nervous system

• Central nervous system

• Somatic nervous system

• Autonomic nervous system