Science Exam Review Flashcards
How can matter be classified?
Into pure substances or input substances (mixtures)
How can pure substances be classified?
By elements or compounds
How can mixtures or impure substances be classified?
Homogeneous mixtures (you chat tell they’ve been mixed) or heterogeneous (and obvious mixture)
How can elements be classified?
Metals, nonmetal, metaloids, noble gases
Physical property:
Physical characteristics that are used to describe a substance or an object (when describing we use it senses)
Physical change:
May change stage but doesn’t become a new substance and most are easy to reverse (includes melting, boiling, freezing, condensation, and sublimation
Chemical change:
The original substance is changed into on or more different substances that have different properties (includes burning, cooking, and rusting)
Chemical change:
Involve producing new substances and are difficult to reverse
Some clues for a chemical change include:
New colour, heat or light is given off, a solid material (called a precipitate) forms in a liquid, bubbles of gas are formed, the change is difficult to reverse
Chemical properties:
Seeing how suns stances (and objects) react with other things. Chemical properties tell us whether something is flammable or if it reacts with an acid or water.
Some chemical properties include:
Combustibility, reaction with acid, & reaction with water
Combustibility:
The ability of substances to react with oxygen to produce carbon dioxide, water and energy (alcohol & gas)
Reaction with acid:
The ability of a substance to fact with acid. Proof includes bubbles and/or a colour change. (Limestone + acid & that produced has bubbles)
Reaction with water:
the ability of a substance to react with water (sodium + water & that produces fumes and gas)
What are he parts of an atom:
Neutrons & protons (in the nucleus) and electrons (circling the outside)
Types of bonding:
Covalent & ionic
Covalent bond:
One or more pairs of electrons are shared by two atoms
Ionic bond:
one or more electrons from one atom are removed and attached to another
Density:
Volume
Volume
Density
Mass
Volume x density
Distance measured in space:
In astronomical units
Solar eclipse;
Occurs when the moon passes between the sun and earth. The moon blocks (occults) the sun. (Can only happen at a new moon)
Lunar eclipse:
Occurs when the moon passed freckly behind the earth into its shadow.
Sunspots:
A spot appearing from time to time on the Suns surface, appears dark by contrast with its surroundings
Flares:
A sudden rapid and intense variation in brightness
Solar flares:
Occurs when magnetic energy that has built up in the solar atmosphere is suddenly released
Big Bang theory:
An event filling all of pace with all particles of the universe rushing away from eachother
Asteroid:
A small rocky body that orbits the sun
Meteror
A small body of matter fork outer space that enters rather atmosphere and appears as a streak of light
Meteoroid:
A small object moving in the solar sisters that would become a meteor of it enter earths atmosphere
Meteorite:
A rocky meteor that survives is passage through the earths atmosphere and it hits the earth
Comet:
A celestial object consisting of j e and dust. (When near the sun, a tail of gas and dust particles point away from the sun)
Revolution of the earth:
The movement of the earth around the sun
Rotation of the earth;
The eart turning on its own axis
Humans in space:
Weightlessness, body fluid imbalance, muscular atrophy, space sickness
