Fundamental Ideas In Chemistry Flashcards
What is the rule that connects protons and electrons?
Protons = electrons. There are always the same number of protons and electrons.
What two subatomic particles can you find in the nucleus?
Protons and neutrons.
Write the charge and mass of a proton, a neutron and an electron.
A Proton has a mass of 1 and a charge of +1. A Neutron has a mass of 1 and a charge of 0. An Electron has a mass of 1/1840 and a charge of -1.
What is the scientific name for the rings drawn around the nucleus? What is the electronic configuration?
Energy shells are the rings around the nucleus. The electronic configuration is the number of electrons that are allowed on each energy shell. 2, 8, 8.
What does the group number of an element tell us?
The group number tells us how many electrons are on the outer shell.
Describe the relationship between the group number and the number of electrons on the outer shell.
If the element is in group one, it has one electron on the outer shell. So, the group number also tells us how many electrons are on the outer shell.
What is the difference between mixtures and compounds?
A mixture is a mix of two elements. They have not been combined during a reaction and can be separated easily. A compound consist of two or more elements that have been chemically joined together to form a new substance.
Describe the changes that we see in group one as we move down the column. Why?
The atom gets larger as we move down the group. The reactivity increases and the reactions become more vigorous. The larger the atom, the easier it is to lose the electron on the outer shell because there is a stronger attractive force between the positive nucleus and the electrons on the closer shells. The outer shell has a weaker force of attraction.
What are special about the elements in group 0?
All of the elements in group 0 have a full outer shell of electrons meaning that they are much more stable and don’t react with very much. As you move down the groups the boiling point increases (but stays below zero) and the density increases.
How are positive and negative ions formed?
All atoms want to achieve a full outer shell. They gain or loose electrons in order to achieve this. If they lose electrons POSITIVE ions are formed, if they gain electrons negative ions are formed. An electron was talking to another electron and said “help help I have lost an electron” the other electron replied “are you sure” and the electron said “I’m positive”
What is the attraction between oppositely charged ions called?
An ionic bond.
What happens to the mass of the reactants during a reaction?
In a chemical reaction, the mass of the reactants is equal to the mass of the products.
Practice question. I start with 100g of CaCO3 and I end up with 56g of CaO and an amount of CO2. How much CO2 do I have?
44g. 56 + ? = 100. 100 - 56 = 44. The mass of the reactants must equal the mass of the products.
