Chemistry test 1 Flashcards
What is hydrogen at room temperature?
Gas
Is chemical or physical bonding stronger?
Chemical
All … are made up of atoms
Substances
How many groups are there in the periodic table?
8
Elements contain only … type of atom
one
Compounds contain more than one type of …
atom
An atom has a … at its centre, surrounded by electrons (in the shells)
Nucleus
An atom has a nucleus containing …
Protons and Neutrons
Protons have a … charge
Positive
Neutrons have a … charge
Neutral
Electrons have a … charge
Negative
What is an isotope?
Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.
… are atoms of the same element with the same number of protons but different numbers of neutrons.
Isotopes
What is the relative atomic mass of an element?
The average mass of the atoms of an element taking into account all of the isotopes of that element
What is the relative atomic mass of Bromine?
80
What is the relative atomic mass of Neon?
20
What is the relative atomic mass of Aluminium?
27
Where are transition metals positioned on the periodic table
Between groups 2 & 3
True or False: Transition metals are highly reactive
False
True or false: Transition metals can form positive ions with different charges
True
True or False: Transition metals form coloured compounds and are useful as catalysts
True
True or False: Transition metals have similar properties to alkali metals
True
Y/N: Are the transition metals harder and stronger than the alkali metals?
Yes
Y/N: Is aluminum a transition metal?
No
Noble gases are very u………
Unreactive
Does the boiling point of Noble Gases (increase / decrease / stay the same) as you go down the periods in the periodic table?
Increase
Why are the Noble Gases highly unreactive & why do they form molecules?
Their atoms have a full outer shell of electrons
what are the physical properties of transition metals?
-Shiny
-Conduct heat & electricity
-Strong & hard
-Higher density than group 1
-Higher melting point than group 1 (except Hg (Mercury))
what are the physical properties of alkali metals?
-Shiny when freshly cut
-Very soft
-Good thermal and electrical conductors
-Relatively low density
-Relatively low melting point
Where are the alkali metals positioned on the periodic table?
Group 1
What is the order of groups in the periodic table?
1,2,3,4,5,6,7,0
How did John Dalton arrange the elements in his “Table of Elements”?
In order of atomic weight
How many elements did John Dalton know about to include in his “Table of Elements”?
20 elements
Name the 3 men who worked to develop a Periodic Table of Elements in the 19th Century
-John Dalton
-John Newlands
-Dimitri Mendelev
What does a group refer to in the periodic table?
A column of elements going down the table
What happens to reactivity as you go down group 1?
Reactivity increases
How many electrons do group 7 elements gain and what ion do they form?
Gain 1 electron and form a 1-ion
How did Mendelev arrange the elements in his table?
By atomic mass and similar properties
Why did Mendelev leave gaps in his table?
He predicted elements that had not been discovered yet
The average mass of the atoms of an element taking into account all of the isotopes of that element
Relative atomic mass
Tomson’s plum pudding model (1897)
-Mass of positive charge
-Negative electrons
Rutherford - Bohr model (1913)
-Positive nucleus containing protons
-Negative electrons in shells
Chadwick model (1932)
-Positive nucleus containing neutrons and protons
-Negative electrons in shells
How many electrons does the first shell hold
2
How many electrons does the second shell hold
8
How many electrons does the third shell hold
8
Relative atomic mass of chlorine
**Ar=(35x75.8)+(37x24.2)=
**75.8+24.2
