Topic 1 - Let's React Flashcards
What is an atom?
All of the materials around us made up of tiny building blocks
Describe the structure of an atom
proton and neutrons inside of nucleus
electrons on shells outside
What is the charge of a proton?
positive
What is the charge of a neutron?
no charge
What is the charge of an electron?
negative
Explain what is meant by a neutral atom
there are equal amount of protons and electrons
How do you find the amount of neutrons in an atom?
mass number - protons = neutrons
What is the electron shell arrangement?
2,8,8,2
What does heating an element do?
- electron to absorb energy and jump to a higher energy level or shell
- electron is excited and unstable and quickly returns to a lower energy level releasing a fixed amount of energy
How is coloured light released?
when the electron returns to the lower energy level and releases a fixed amount of energy or photon.
What colour does lithium produce?
red
What colour does sodium produce?
yellow
What colour does copper produce?
blue
What colour does barium produce?
green
Why are valence shell electrons important?
It determines how an atom behaves when it
meets another atom.
(reactivity of it)
Relate the number of valence electrons to the group number on the periodic table
The number of electrons in the valence shell is the number group the element is in.
eg. chlorine (17) is in group 17.
What is an ion?
an atom or molecule with a net electric charge due to the loss or gain of one or more electrons
What is a cation?
positive ion that loses electrons to have a full outer shell
What is a anion?
negative ion that gains electrons to have a full outer shell
Which type of element forms cations?
metals
Which type of element forms anions?
non metals
Why do atoms form ions?
to become stable and have full outer shells
Explain how bonds form between ions
Ionic bonds form between two or more atoms by the transfer of one or more electrons between atoms.
state the Law of Conservation of mass in chemical reactions
mass cannot be created or destroyed during a chemical reaction, so the total mass of reactants must equal the total mass of products
List the experimental observations indicating that a chemical reaction has occurred
bubbles
change in colour
odour
What are the reactants of a chemical reaction?
the starting materials in a reaction that undergo a chemical change to form a product
What are the products of a chemical reaction?
the atoms and molecules produced by the reaction
Describe the difference between a physical and a chemical change.
Physical changes are those in which the shape, size, or state of the matter changes, but the substance is still essentially the same, whereas chemical changes are those where one or more substances are combined to produce a new substance
List experimental observations that indicate a chemical change
colour change
temperature change
What is the rate of a chemical reaction?
the speed at which a chemical reaction occurs
What are the factors that can increase the rate of a chemical reaction?
- increased temperature
- increased concentration
- increased surface area
- catalyst
How does an increased temperature increase the rate of chemical reaction?
When you heat an object, is causes vibrations, making particles moving quicker, meaning there are more collisions occuring, therefore a quicker reaction rate.
How does an increased concentration increase the rate of chemical reaction?
With a higher concentration, there are more particles in the space meaning they are more likely to collide with each other and react quicker.
How does an increased surface area increase the rate of chemical reaction?
This means a solid is split into serveral pieces with an increased surface area for the reactant particles to collide with.
small pieces = large surface area = more collisions
How does a catalyst increase the rate of chemical reaction? eg
catalysts provide a surface for the reaction to take place on increasing the frequency of collisions.
eg. nickel
