Chapter C2- The Periodic Table Flashcards
What are the properties of metals?
What are all of the group 1 elements called?
Why are they called this?
What are alkalis also called?
Malleable (hammered into shape) Dense (usually) High melting point Good conductors of heat and electricity Shiny (when freshly cut). Ductile (drawn, stretched or pulled into wires). Sonorous (makes a sound when dropped).
Alkali metals.
Because they all form alkaline solutions when they react with water.
Hydroxides.
What do group 1 elements do with group 7 elements?
What are group 7 elements also called?
What are group 7 ions called?
What happens in group 7 the further up you go unlike in group 1?
What are the properties of transition elements compared to alkali metals?
What happens when transition elements react with oxygen or water?
What two things happens to larger atoms going down a group in the periodic table?
What do halogens tend to do when they form chemical bonds?
What do alkali metals tend to do when they form chemical bonds?
Readily react with each other.
Halogens (which are also highly poisonous).
Halides.
The more reactive they become, whereas in group 1 they become less reactive.
They have higher melting points and densities, they are stronger and harder and are much less reactive.
They don’t react vigorously with oxygen or water.
- Larger atoms lose electrons more easily going down a group.
- Larger atoms gain electrons when they form chemical bonds.
Halogens tend to gain electrons.
Alkali metals tend to lose electrons.
What are catalysts?
How are elements fitted into groups?
What do elements in the same group do?
What three things are weird about alkali metals compared to other metals in the periodic table?
What type of electron shell do transition metals contain?
What are the three magnetic metals?
What is an alloy?
What does the reactivity of an element depend on?
What do metal atoms tend to do with electrons?
What do non-metal atoms tend to do with electrons?
Substances that can increase the rate of a reaction. The catalysts remain unchanged at the end of the reaction it catalyses.
According to the number of electrons in their outer shell.
Behave in similar ways chemically.
They aren’t dense (ie they float in water); they are soft; they melt at low temperatures.
D-sub shell (D-block elements).
Iron, nickel and cobalt.
A mixture of two elements, one of which is a metal.
How easily its atoms lose or gain electrons.
Lose electrons when they react with non-metals.
Gain electrons when they react with metals.
What did Mendeleev do when organising the periodic table?
What did Nealands do?
Put the elements that were discovered of the time in order of atomic number, and left spaces where he predicted that the elements would fit in.
Arranged elements in order of mass, noticed that the properties of any eighth element was similar and produced a table but thought that all the elements had been discovered despite chemists still discovering new ones all the time.
How were elements arranged in the early 1800’s?
What until quite recently were the three obvious ways to categorise elements?
What four things did scientists at the time have no idea of?
What did this mean that there was no such thing as?
What two things were discovered in the 20th century that enabled elements to be arranged in order of atomic number?
What was the only thing that scientists could measure and so what was the result of this?
What was then noticed once this was completed?
What were two disadvantages of early periodic tables?
For what two reasons was this?
Elements were arranged by atomic mass
- Their physical properties
- Their chemical properties
- Their relative atomic mass
They had no idea of atomic structure or of protons, neutrons and electrons
Atomic number to them
After protons and electrons were discovered
Relative atomic mass and so known elements were arranged in order of atomic mass
A periodic pattern was noticed in the properties of elements
They were not complete and some elements were placed in the wrong group
Because elements were placed in the order of relative atomic mass and did not take into account their properties.
What did Dmitri Mendeleev do?
When did he do this and how?
What did Mendeleev mainly put them in order of except for when and why?
What is an example of this changing of order?
Why were gaps left in his periodic table?
What did some of these gaps indicate and what did this allow Mendeleev to do?
What two things then later happened that helped confirm Mendeleev’s ideas?
Left gaps and predicted new elements
In 1869, by taking 50 known elements and arranging them into his Table of Elements- with various gaps
In order of atomic mass but did switch that order if the properties meant it should be changed
If elements have similar properties to the elements in that group
To make sure that elements with similar properties stayed in the same groups
The existence of undiscovered elements allowing him to predict what their properties might be
When they were found and fitted the pattern.
What was confirmed of Mendeleev’s ideas when what was discovered and when?
What do isotopes of the same element have that’s different but also have that’s the same?
What does this mean that isotopes do in the periodic table?
The discovery of isotopes in the early 20th century confirmed that Mendeleev was correct not to place elements in a strict order of atomic mass but to also take account of their properties
Isotopes of the same element have different atomic masses but have the same chemical properties
They occupy the same position on the periodic table.
