C1- Atomic structure Flashcards
What is the smallest part of an element that can exist?
An atom
How many different elements are there?
About 100
How are compounds formed?
From chemical reactions where bonds are broken and then reformed.
What is a substance made of only one type of atom?
An element
How many letters are there in a chemical symbol?
One or two depending on the element.
What are all substances made from?
Atoms
What is involved in a chemical reaction?
The formation of one or more new substances and usually an energy change.
What is an atom?
The smallest part of an element that can exist.
Where do we find all the different elements?
On the periodic table.
What is an element?
A substance made of only one type of atom.
What are the 3 forms that substances can exist in?
Elements Compounds Mixtures
Does separating a mixture involve a chemical reaction? Explain.
No, it doesn’t involve a chemical reaction because no chemical bonds are being made or broken.
What is a mixture
A substance made of more than one element or compound not chemically bonded together.
What is a molecule?
A substance made of more than one atom chemically bonded together. Can be the same element or differnt elements
What is a substance made from two or more different atoms chemically bonded together?
A compound.
How can mixtures be separated? (5)
Filtration, crystallization, simple distillation, fractional distillation, chromatography
What is Dalton’s model of the atom?
Atoms as solid spheres that could not be divided into smaller parts
Who believed that atoms were solid spheres that could not be divided into smaller parts?
Dalton
What is the plum pudding model of the atom?
Sphere of positive charge with negative electrons embedded in it
What model of the atom is a sphere of positive charge with negative electrons embedded in it?
The plum pudding model.
What did scientists discover in the alpha particle scattering experiment?
Some alpha particles were deflected but he gold foil. This showed that an atom’s mass and positive charge must be concentrated in one small space
What did the scientists observe in the alpha scattering experiment?
That the alpha particles did not go straight thought the foil but were deflected.
What was the conclusion from the alpha scattering experiment?
That the atom’s mass and positive charge must be concentrated in one small area
Describe the nuclear model of the atom
Dense nucleus with electrons orbiting it
