Unit 1: Chapter 1 - Fundamental Ideas Flashcards
The Atomic Structure
What are the charges of protons, electrons and neutrons?
What are the relative masses of P, E and N?
Where are they located?
Within the nucleus there are protons and nucleus. Each of their relative mass is 1, but the protons have a POSITIVE charge whereas the neutrons are NEUTRAL.
Orbiting around the nucleus is the electrons. Their mass is negligible (0) and their charge is NEGATIVE.
What are atoms, elements, compounds and mixtures?
All substances are made of atoms. An atom is made up of a nucleus and electrons orbiting it.
Atoms have their own symbols in the periodic table to identify the element.
Compounds are made of two or more different types of atom and the chemical bonds are held very tightly together. E.g. Water.
Mixtures are a variety of atoms mixed together but are not chemically bonded together.
Arrangement of Electrons
Where is the lowest energy shell located?
How can we find where an element is in a particular group of the periodic table?
Do elements of the same group have the same qualities?
A model of an atom is the electron shell diagram.
The first shell (2 electrons) has the lowest energy level.
The second energy level holds up to 8 electrons and the same rule applies for the third, fourth energy levels and so on.
E.g.
Calcium (20 electrons)
2,8,8,2
^the last electron number determines what group it is in. In this case, Calcium is in group 2.
Elements of the same groups have similar qualities.
Forming Bonds
What is ionic bonding?
What is covalent bonding?
IONIC BONDING
Metal atoms form positively charged ions (+)
Non-metal atoms form negatively charged ions (-)
Opposite charges attract.
Ionic bondings only happen between metals and non-metals.
e.g.
Li(-) + F(+) -> LiF (lithium fluoride)
COVALENT BONDINGS
Non-metals bond to each other in a different way. The outermost shell overlap each other and form a strong bond called COVALENT BONDING. They overlap to produce a full outer shell.
Examples mean H2S, CH4 and H2O
Chemical Equations
What is the general rule of chemical equations?
Reactants -> Products
Whatever is on the reactant side should be the same amount as the product side.
E.g.
CaCO3 -> CaO + CO2
