chemical reactions Flashcards
What is a chemical reaction?
It is when 2 or more elements combine to make a new product.
What is a word equation?
A word equation shows the names of each substance in a reaction.
What is a balanced equation?
A balanced equation gives more information about the reaction because it includes the symbols of the things involved.
How do you write balanced equation?
You replace the name of each substance with its symbol or formula and use numbers to balance the equation.
Is this a balanced equation Cu + O2 → CuO?
Cu + O2 → CuO is not a balanced equation because there is 2 oxygen on one side and only one on the other so it is not balanced. 2Cu + O2 → 2CuO this is a balanced equation.
What is a Combustion reactions?
Combustion reactions is another name for burning.
What do non metals react with to produce non metal oxide?
They react with oxygen to make non metal oxide
what is an exothermic reaction?
Exothermic reaction is when energy is given out to the surroundings. It is when it gets hotter.
What is an endothermic reaction?
An endothermic reaction is when energy is taken from the surroundings so the temperature falls.
What is thermal decomposition?
Thermal decomposition is when Some compounds break down when heated, forming two or more products from one reactant.
What is thermal decomposition an example of?
Thermal decomposition is an example of an endothermic reaction.
What is a catalyst substance?
A catalyst is a substance that speeds up reactions
What is a bond?
The chemical link that holds molecules together.
What is a product?
A substance formed in a chemical reaction.
Is everything made from an atom?
Yes.Even us!
How many atoms are in the world?
There are over 100 different atoms in the world and these are called elements.
What is an element?
something that only contains one atom type.
How are chemical symbols written?
Every chemical symbol starts with a capital letter, with the second or third letters written in lower case.
What does the chemical Li stand for?
Lithium.
Are the chemical symbols the same all over the world?
Yes that is why some are wired like W stands for tungsten.
The horizontal rows in the periodic table are called?
Periods.
The vertical columns in the periodic table are called?
Groups.
Are elements in the same group similar to each other?
Yes.
Are the non metals on the left?
No they are on the left and the metals are on the right.
Is hydrogen a non metal?
Yes but is is often put in the middle of the table.
Are most elements metal or non-metal?
Most elements are metal.
Are atoms the building blocks of everything?
Yes.
Will you only ever see elements in the periodic table?
Yes no compounds.
