Atoms, Elements And Compounds (ch2) Flashcards
(69 cards)
1
Q
What is the smallest particle of an element?
A
An atom is the smallest particle of that element.
2
Q
What are sub-atomic particles?
A
Sub-atomic particles include protons, neutrons, and electrons.
3
Q
What is the charge of a proton?
A
A proton has a charge of +1.
4
Q
What is the charge of an electron?
A
An electron has a charge of -1.
5
Q
What is the charge of a neutron?
A
A neutron has no charge.
6
Q
What is the relative mass of a proton?
A
The relative mass of a proton is approximately 1.
7
Q
What is the relative mass of a neutron?
A
The relative mass of a neutron is approximately 1.
8
Q
What is the relationship between protons and electrons in an atom?
A
In an atom, the number of protons equals the number of electrons.
9
Q
What is the structure of an atom?
A
An atom consists of a nucleus surrounded by shells of electrons.
10
Q
What is electronic structure?
A
The arrangement of electrons in orbits/shells.
11
Q
What is the maximum number of electrons in the first shell?
A
2 electrons.
12
Q
What is the maximum number of electrons in the second shell?
A
8 electrons.
13
Q
What is the maximum number of electrons in the third shell?
A
8 electrons.
14
Q
What is the maximum number of electrons in the fourth shell?
A
18 electrons.
15
Q
How are elements arranged in the periodic table?
A
In a list of increasing proton number order.
16
Q
What separates metals from non-metals in the periodic table?
A
A zig-zag line/staircase diagonal.
17
Q
What are the groups of elements in the periodic table?
A
I, II, III, IV, V, VI, VII, and transition elements.
18
Q
Where are metals located in the periodic table?
A
On the right-hand side (R.H.S).
19
Q
Where are non-metals located in the periodic table?
A
On the left-hand side (L.H.S).
20
Q
What is the Periodic Table?
A
A tabular arrangement of chemical elements.
21
Q
What is a Period in the Periodic Table?
A
Horizontal rows in the periodic table, running left to right.
22
Q
How many periods are there in the Periodic Table?
A
There are a total of 7 periods.
23
Q
What are Groups in the Periodic Table?
A
Vertical columns in the periodic table.
24
Q
How many groups are there in the Periodic Table?
A
There are a total of 8 groups.
25
What is the relationship between protons and neutrons?
The atomic mass is the sum of protons and neutrons.
26
What is valence electron?
Electrons in the outermost shell that determine chemical bonding.
27
What does the group number indicate?
It indicates the number of valence electrons.
28
What does the period number indicate?
It indicates the number of electron shells occupied.
29
What is the atomic number (P) of an element with 11 electrons?
The atomic number (P) is 11.
30
How many valence electrons does an element with atomic number 11 have?
It has 1 valence electron.
31
How do you calculate the number of neutrons in an atom?
Number of neutrons (n) = Atomic mass - Atomic number.
32
What is the period number for an element with 9 electrons?
The period number is 2.
33
What is the electron configuration for an element with atomic number 9?
The electron configuration is 2, 7.
34
What does the term 'valence shell' refer to?
The valence shell is the outermost shell of an atom.
35
How can you determine the position of an element in the periodic table?
The number of valence electrons and the occupied electronic shells indicate its position.
36
What are Isotopes?
Atoms of the same element, with same number of protons and electrons but different number of neutrons
37
What to do when naming an isotope?
Write/ mention nucleon number
E.g: Hydrogen-1 or Hydrogen-2
38
Why is sometimes Ar not a whole number?
Ar is the average mass of all the isotopes of an element
39
What is more closer to the isotope and have greater isotopic proportion?
Ar is more closer to the isotope with greater isotopic proportion
40
What are the similarities of isotopes?
Same number of protons, electrons, valence electrons.
Same electronic structure/configuration and same chemical properties
41
What are the differences in isotopes?
Difference in neutron number, nucleon number/ atomic mass and difference in physical properties.
E.g: M.P and B.P or density or solubility
42
Why do atoms form bonds?
To achieve noble gas electronic structure/ configuration i.e. fully filled outer shells and become stable.
43
What is ionic bonding?
An ionic bond is formed by a complete transfer of electrons from a metal to a non-metal.
Metal loses electron and non-metal gains electron
44
Why does an atom have no charge?
Protons are positively charged. Electrons are negatively charged.
Number of protons = Number of electrons. So, overall charge is zero/neutral.
45
What happens to a metal in an ionic compound?
It loses electron/electrons.
It becomes a positive ion.
It has more protons, less electrons.
It is known as Cation.
Name of Cation remains the same as the atom
46
What happens to a non-metal in an ionic compound?
It gains electrons.
It becomes a negative ion.
It has more electrons, less protons.
It is known as an Anion.
Name of anion is different from its atom,
mostly a suffix—ide.
47
What is the structure of an ionic bond?
Giant ionic lattice
48
What does lattice mean?
Orderly arrangement of particles
49
What does ionic lattice mean?
Orderly arrangement of alternating particles (positive and negative particles)
50
What is the type of force in an ionic bond?
Strong electrostatic force of attraction between positive and negative ions.
51
What are the physical properties of an ionic compound?
1. Have high M.P and B.P due to strong electrostatic force of attraction b/w oppositely charged ions and greater amount of heat energy needed to overcome the bonds.
2. It conducts electricity when molten or in aqueous solution as it has freely moving ions
3. It is soluble in water and insoluble in organic solvents
52
What is covalent bonding/ How are covalent bonds formed?
Covalent bonds are formed by sharing of electrons between non-metals only.
53
Covalent bonds structure?
Covalent bonds have simple molecular structure with weak intermolecular forces
54
What are the physical properties of covalent bonds and why?
1. Low M.P and B.P due to weak intermolecular attractive forces and needing less heat energy to overcome the bonds.
2. It doesn’t conduct electricity as there are no freely moving electrons present.
3.insoluble in water, soluble in organic solvents.
4. Mostly gases or liquids at r.t.p
55
Explain in structure and bonding why NACL has higher M.P and B.P than CO2?
Sodium chloride has giant ionic lattice with electrostatic forces between oppositely charged ions which require more heat energy to overcome. But, carbon-dioxide has simple molecular structure and covalent bonds with weak intermolecular forces which needs less heat energy to overcome.
56
What are the three different types of giant covalent molecule?
1. Diamond
2. Graphite
3. Silicon dioxide/Silica/Sand/Silicon (4) oxide
57
Diamond and graphite introduction?
Diamond and graphite are pure elements which are the allotropes of carbon. They have different structural forms of same element.
58
What is the structure of diamond?
In diamond each carbon atom is covalently bonded to four carbon atoms which are bonded to four more, making a continuous tetrahedral 3-dimensional giant covalent molecular structure, containing many strong covalent bonds.
59
What are the properties of diamond?
1. It is hard and strong, so it is used in cutting and boring.
Reason: it has continuors 3-dimensimal giant
molecular structure
with many strong covalent bonds with are difficult to break.
2 . very high m.p and b.p
It has continuas 3-dimensional
giant molecular structure with many strong covalent bonds which require a lot of heat energy to overcome.
3. Poor electrical conductor
It doesn’t contain freely moving ions and all four valence electrons of each carbon atom are used in bonding
60
What is the structure of graphite?
In graphite, each carbon atom is covalently bonded to 3-carbon atoms which are covalently bonded to 3 more, making a giant molecular structure consisting of hexagonal layers of carbon atoms, with weak attractive forces between adjacent layers.
61
Properties of graphite?
1. Soft and slippery
—> used in pencil lead
—> used as dry lubricant
Reason: has layered structure with weak attractive forces between adjacent layers which are easy to overcome.
2. Good electrical conductor
Because contains freely moving electrons and each carbon is covalently bonded to 3 other carbon atom so one valence electron of each carbon atom is left free, that is responsible for electrical conduction.
62
What is the difference between diamond and graphites structure?
In graphite, each carbon atom is covalently bonded to 3-carbon atoms which are covalently bonded to 3 more, making a giant molecular structure consisting of hexagonal layers of carbon atoms, with weak attractive forces between adjacent layers.
But
In diamond each carbon atom is covalently bonded to four carbon atoms which are bonded to four more, making a continuous tetrahedral 3-dimensional giant covalent molecular structure, containing many strong covalent bonds.
63
What is the structure of silicon dioxide?and what is it used in?
In silicon dioxide, each silicon atom is covalently bonded to 4-oxygen atoms and each oxygen atom is covalently bonded to 2-silicon atoms, making a continuous 3 dimensional giant molecular structure.
It is used in cement and glass manufacturing.
64
Explain in terms of structure and bonding why CO2 has lower m.p and b.p than diamond/graphite/silicon-dioxide?
It (carbon dioxide) has simple molecular structure and covalent bonding with weak intermolecular forces which are easy to overcome.
It (diamond/graphite/silicon-dioxide)has giant molecular structure with many string covalent bonds which are hard to overcome.
65
What is the structure of metal?
It is a lattice of positive metal ions surrounded by a sea of delocalised electrons.
66
How is a metallic bond formed?
The metal atom loses its valence electron very quickly and becomes cation.
Electrons are said to be delocalised.
67
Structure of metallic bonds?
Metallic bond is the strong electrostatic force of attraction between metal cation and sea of delocalised electrons
68
Properties of metallic bond? And why?
1. High m.p and b.p
Because within the metal lattice there is strong metallic bond which requires more energy to overcome.
2. It is malleable and ductile
Because within the metal lattice, metal ions are orderly arranged in layers which can slide over each other.
3. Good electrical conductor as it contains a sea of delocalised electrons.
4. Shiny silvery solid
5. Sonorous —produces ringing sound when hit
6. High density
Because within a metal lattice, metal ions are closely packed together hence more mass packed per unit volume.
69
What is an alloy? And what are the differences between alloy and pure metal?
An alloy is a mixture of metals.
A pure metal has same sized atoms which are orderly arranged in layers and can slide over each other.
But
An alloy has different sized atoms which are not orderly arranged in layers and it is difficult for atoms to slide over each other
