C3 Atoms, Elements Compounds Flashcards
Which group are the noble gases in the periodic table
Group 8
Why are the noble gases very unreactive
They have a full outershell, meaning they have the most stable electronic configuration
What is the most stable electron configuration
A full outer shell of electrons. Atoms react in order to gain a full outer shell of electron, so that they become more stable
Why are alloys harder than pure metals
Atoms in pure metals are in arranged uniform rows which can easily slide over each other making them malleable. Alloys contain different sized atoms which disort layers and are unable to slide. This makes it hard
Alloy
A mixture containing metals and another element
Covalent bond
A bond formed when two non metals share a pair of electrons
Isotopes
Atoms of an element with the same number of protons but a different number of neutrons. Ie same atomic number but different mass number
How are ions formed
Postive ions form when an atom loses electrons. Negative ions form when an atom gains electrons
What are ions
Atoms or groups of atoms with a positive or negative charge
What does atomic number represent
The number of protons in an atomic nucleus
What are cations ans anions
Cation-positive ion
Anion-negative ion
What types of elements are ionic bonds formed between
Between metals and non metals.
-Metals lose electrons to form positive ions.
- Non metals gain electrons to become negative ions.
Why do elements in the same group have similar chemical properties
Cuz they have the same number of electrons in the outer shell which determines how they react
How are elements arranged in the modern periodic table
In order of increasing atomic number. Elements with similar properties are in the same column
What does the mass of an atom mean?
The total number of protons and neutrons found in the nucleus of an atom
Why do atoms contain equal number of protons and electrons
Atoms are stable with no overall charge. There must be an equal number for the charges to balance
What are the relative charges of protons, neutrons and electrons
Proton: +1
Neutron: 0
Electron: -1
What does period(row) tell you about all the elements in that period
They have same number of electron shells. All elements in peiod 4 have 4 electron shells.
Why do ionic compounds have high melting and boiling points
Cuz they have strong electrostatic attraction between the oppositely charged particles. This requires a lot of energy to overcome meaning high melting and boiling points
Desbribe the properties of a diamond
Very hard due to covalent bonding
Very high melting point due to covalent bonds
Explain why metals are malleable
The ions are aaranged in regular uniform rows. These rows are able to slide over each other easily, making the metals malleable
Difference between element and compound
An element is a substance made out of only 1 type if atom, whereas a compound is made up of two or more chemically combined elements
Relative masses of protons, neutrons and electrons
Proton 1
Neutron 1
Electron 1/1836
Two types of isotopes
Radioactive and non radioactive
Solvent
A substance that dissolves to form a solution
Concentration
A substance dissolved in a solution
Mixture
Contains two or more elements or compounds that arent chemically combined
Industrial use of radioactive isotopes
Smoke alarm tracker
Explain the difference in melting and boiling points in the different types of covalent structured
Giant bonds-high boiling and melting point
Small bonds- low
How are bonds formed between 1 and VII elements
G1 elements only lose 1 outer shell electron to form 1+ ions. Group VII elecment needs 1 ion in the outer shell that had 7 electrons. It gains 1- charge to form an ionic bond
Non metal
Gain electrons to form negative ions. Top right in periodic table
Metal
Lose electrons to form positive ions. Left side of the periodic table
Why do atoms form covalent bonds
To obtain a more stable electron configuration
Medical use of radioactive isotopes
Cancer treatment
Lung imaging
Compare the solubility of ionic and covalent compounds
Ionic compounds are generally solubke in water, covalent compounds are insoulble in water
What is brass? What are its uses
An alloy of copper and zinc.
Its hard and resistant to corrosion. It is used for decorative hardware such as plumbing fittings
Name 2 giant structures formed from carbon atoms
Graphite
Diamond
How are electrons arranged in an atom
In shells around the nucleus. The maz number of electrons in the first 3 shells is 2, 8,8
How does electrical conductivity compare in the ionic and covalent compound
Covalent compounds dont have free compounds so they dont conduct electricity
Ionic compounds conduct electricity in a molten or aq form
Metallic bonding
Giant lattice structure with a regular arrangement of positive metal ions held together in a sea of delocalised electrons.
Uses of graphite? Why?
Electrodes bc it conducts electricity and has a high melting point.
Lubricant cuz its slippery
Structure of graphite
Each carbon atom bonded to other 3 carbon atoms
Layers od hexagonal rings of carbon atoms
Weak intermolecular forces between layers
Structure of silicon oxide
Each silicon atom is covalently bonded to 4 oxygen atoms
No delocalised electrons
Each oxygen atom is covalently bonded in 2 silicon atoms
Why is diamond used in cutting tools
Its very hard
Which properties do the structured silicon dioxide and diamond share
Very hard
Insoluble in water
Don’t conduct electricity
Properties of graphite
High melting point
Slippery
All carbon atom are covalently bonded to four other carbon atoms
No delocalised electrons
