science term 2 Flashcards
what is newtons first law
An object’s motion will not change unless a force acts upon it. This is also known as the law of inertia.
what is newtons second law
F = ma
The acceleration of a moving object depends upon its mass and the force acting on it”.
what is newtons third law
For every action there is an equal and opposite reaction
distance meaning
Distance is a measure of how far apart objects are.
displacement meaning
Displacement is the direct length between any two points when measured along the minimum path between them
how to calculate displacement and distance
To calculate distance, the direction is not considered. To calculate displacement, the direction is taken into consideration.
speed features
- scalar quantity
-magnitude but no direction
-use distance to calculate speed
velocity features
- vector quantity
- magnitude and direction
-we use displacement to calculate velocity
graph shows
straight line- constant velocity
go up- acceleration
go down- negative acceleration
bottom straight- stationary
what is acceleration
acceleration is a change in an object’s velocity over time
what is velocity
velocity is the speed acting on a certain direction
atoms
Atoms are the particles that make up all the substances in the universe.
Nucleus
The centre of each atom is its nucleus. It is a tight, dense, bundle of protons and neutrons.
Protons
Protons carry a positive charge (+)
neutrons
Neutrons have a neutral charge and no charge
electrons
electrons are negatively charged they attract to the positive nucleus.
Elements
Because electrons are negatively charged they attract to the positive nucleus.
electron shell
2/8/8/16/32
atom
the number of Protons and Electrons are equal in a neutral atom
mass number
number of protons + number of neutrons
Group 1 metals
alkali metals and they are very reactive, conduct heat and electricity.
group 2 metals
alkaline metals they are not as reactive as alkali metals
group 4-12
are known as the transition metals. Much denser, stronger and harder than group 1 elements, however they are less reactive than the metals in group 1.
Group 18
is known as the noble gases. Also known as the inert gases because they are unreactive
ions
An ion is like an electrically charged building block of matter. It’s formed when an atom gains or loses electrons, giving it a positive or negative charge. Imagine it as a tiny electrically charged particle.
cation
A cation is an ionic species with a positive charge.
anion
negatively charged ion,
