Chemistry Flashcards
What is a mixture?
A mixture is a substance made up of at least two different substances that are not chemically bonded together
What is a compound
A compound is a pure substance formed when two or more elements are chemically bonded together
What did the model of Democritus say?
Democritus’s model first suggested that all substances consisted of tiny indestructible particles called atoms
What did Daltons model suggest
Daltons theory suggested that all mater consisted of tiny particles called atoms,atoms couldn’t be divided,atoms of the same element were alike and atoms combined in to simple whole number ratios.
What did Thomsons model suggest
It suggested that the atom was a positively charged sphere containing negatively charged particles called electrons.
What did rutherfords model suggest
His model suggest that the atom consisted of mostly empty space with a dense nucleus containing positively charged protons in the centre and negatively charged electrons that orbit the nucleus. It also said that the orbiting electrons would lose energy and spiral into the nucleus.
What did Bohrs model suggest
It was the same as rutherfords but it suggested that the orbiting electrons were at different energy levels and that electrons could move from level to level by gaining or losing energy.
What did chadwicks model suggest.
It suggested that the nucleus contained particles called neutrons that had no electric Charge and a mass about the same as a proton
A pure substance is ?
A substance containing only one type of particle.
Elements and compounds are examples of pure substances.
