Unit 1 Flashcards
C2H4 and H2 were reacted to form C2H6. Using the formulas of the substance, state if a new compound has been formed.
Yes, a new compound has been made as the atoms in C2H6 are in different proportions as they were in the previous compounds.
Argon can be separated from air. will the chemical properties of argon be different in air and in its pure form.
no, the properties will be the same as argon is only an element in a mixture and chemical properties are not affected by being in a mixture.
Describe 3 similarities between the plum pudding model and the nuclear model of the atom.
they both have areas of positive charge they both have electrons they are both neutral overall
Describe 3 differences between the plum pudding model and the nuclear model of the atom.
-Plum pudding model does not have neutrons or protons. it only has electrons surrounded by a positive charge. -Plum pudding doesn’t have shells of electrons as the electrons are arranged randomly -Modern nuclear model has a concentrated mass but plum pudding model has an evenly spread mass.
Both of calciums electrons are in the innermost shell. why is this.
The electrons in an atom occupy the innermost sell first which can hold 2 electrons
How did the discovery of isotopes explain why atomic weights dont always give the correct order of elements.
isotopes have a different number of neutrons but the same chemical properties. This means they give different mass readings which don’t always coincide with the correct order of elements.
Why is the table caled the periodic table?
similar properties occur at regular intervals
Study Element X
What group is element X in and why.
2nd group because it has 2 outer shell electrons
Study element X
What period is element X in and why.
3rd period because it has 3 shells of electrons
Where are metals found on the periodic table?
bottom and left
Where are non metals found on the periodic table?
right and top
Suggest 1 physical property that magnesium and aluminium have in common.
strong
electrical conductivity
malleable
Compare the physical properties of iron and sulfur.
iron is a strong shiny metal, sulfur is a briittle powder
iron has a high melting point, sulfur has a low melting pont
iron conducts, sulfur doesnt
What happens to melting point as you go down group 1?
it decreases
Compare the reactivity of francium to caesium. justify your answer using electron arrangement.
francium is more reactive than caesium because the further down the group you go, the further the outer shell is from the nucleus. this means the attraction decreases so the lectron is more easily lost.
Dscrible the electronic structure of halogens and explain how it changes down group 7
the halogens have 7 elecrons in their outer shell. as you go further down the group additional shells are added so the outer shell is further from the nucleus
