Grade 9 Science Exam Review

A collection of vocabulary flashcards based on key concepts from the Grade 9 science lecture notes.

Atomic Number

The number of protons in the nucleus of an atom, which determines the element's identity.

Noble Gas

Elements in group 18 of the periodic table, characterized by their lack of reactivity due to having a complete valence shell.

Halogen

Elements in group 17 of the periodic table which are known for their high reactivity and tendency to form salts with metals.

Proton

A subatomic particle with a positive charge found in the nucleus of an atom.

Neutron

A subatomic particle with no charge, also found in the nucleus of an atom.

Electron

A negatively charged subatomic particle that orbits the nucleus of an atom.

Chemical Change

A change that involves the formation of one or more new substances, with different properties and compositions.

Physical Change

A change that affects one or more physical properties of a substance without altering its chemical composition.

Density

The mass of an object divided by its volume, often measured in grams per cubic centimeter (g/cm³).

Big Bang Theory

A scientific explanation for the origin of the universe, stating that it began as a singularity and has been expanding ever since.

Gravitational Accretion

The process through which matter falls together due to gravity, contributing to the formation of stars and planets.

Red Shift

The phenomenon where light from an object moving away is stretched to longer wavelengths, indicating the object is receding.

Blue Shift

The phenomenon where light from an object moving closer is compressed to shorter wavelengths, indicating the object is approaching.

Keystone Species

A species that has a disproportionately large effect on its environment relative to its abundance, crucial for maintaining the structure of an ecosystem.

Dynamic Equilibrium

A state in which a system is balanced and stable, with continuous changes occurring that do not alter the system's overall conditions.

Carbon Cycle

The cycle through which carbon is exchanged among the atmosphere, land, water, and living organisms.

What did dalton Create

The Billard ball model that shows the atoms are small and d invisible and rearranged to form new substances

What did Thompson

Thompson created the plum pudding model which chose that negatively charged atoms are spread throughout the positively charged atom

What did Rutherford create?

He used the gold foil experiment to prove that electrons are located in the

Empty space of an atom

what did Bohr create

Electrons exist in the energy levels and can jump between the levels

Why would potassium be more reactive than neon?

Potassium would be more reactive than neon because potassium is an alkaline metal and alkaline metals have one extra electron in there outer shell, which makes them want to lose it to become stable so it reacts easily with other elements

Universe

A lot of galaxies

singularity

Where the universe began

Galaxy

Massive system of stars

Nuclear fusion

Two or or more elements combing together

Gravity

Constant force pulling objects together

Nebula

A cloud of gas and dust drifting in space

Supernova

Where a star collapses on its self and explodes

Black hole

Object so dense not even light can pass through