Topic 1 Flashcards
(50 cards)
What are atoms composed of ?
Protons, electrons and neutrons
Define an element ?
Something which is made up of 1 type of atom and has a symbol on the periodic table
What is an isotope ?
Different forms of the same element,which have the same number of protons but a different number of neutrons
Define relative atomic mass?
An average mass taking into account the different masses and abundances of all the isotopes that make up the element
What is the history of the atom?
1800-Dalton,each chemical element had its own atom
1877 to 1906-Thompson,tiny negatively charged and bigger particles positively charged
1909-Rutherford,scattering experiment electrons were orbiting the nucleus which contains protons
1914 to 1932-Bohr’s,electrons were in a fixed energy level
What is a compound?
They are made up of two or more elements chemically bonded together. They also have a formula eg H2O
What do formulas show ?
Which atoms are in a compound
Finish the sentence
Chemical changes are shown …….
Using chemical equations eg if methane burns in oxygen giving carbon dioxide and water
= methane+oxygen - carbon dioxide+water
What is the difference between a compound and a mixture?
A mixture is not chemically bonded and can therefore be split
Who were the two people who came up the the periodic table and what did the do
Newlands-arranged in order off mass
- every 8th element had similar properties
-not believed as it didn’t work for all elements
Mendeleev-order masses but swapped a few to fit a pattern
-left gaps for undiscovered elements and predicted properties
Which elements go in Group 1 of the periodic table?
Group 1-alkali metals
Finish the sentence
Metals are element which can form….
Positive ions when they react
What are the difference between metals and non-metals ?
Metals are strong but are malleable
Metals are good at conducting heat and electricity and non metals aren’t
Metals have high boiling and melting points and non metals do not
What are the 6 group 1 elements ?
They are lithium, sodium, potassium, rubidium, caesium and francium
What are 3 trends of alkali metals?
Increasing reactivity down the group
Lower melting and boiling points
Higher relative atomic mass
Describe florine?
Florine-very reactive, poisonous yellow gas
What are the 3 trends in the halogens?
They become less reactive
Have a higher melting point
Have higher relative atomic masses
Name the 5 noble gases ?
helium, neon, argon, krypton, xenon, radon
Describe iodine?
Iodine is a group 7 element and is dark grey crystalline solid or a purple vapour
Describe bromine ?
Bromine is a group 7 element and is a dense, poisonous, red-brown volatile liquid
Describe chlorine?
Chlorine is a group 7 element and is fairly reactive,poisonous dense green gas
What is the last group 7 element?
Astatine
Why are noble gases unreactive ?
They have 8 electrons therefore a full outer shell meaning they are unreactive
What type of gases are noble gases ?
They exist as monatomic gases-they are not bonded together
