Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
82 Cards in this Set
- Front
- Back
|
Where is most of the atom's mass concentrated?
|
In the nucleus
|
|
|
Why are relative mass and relative charge of subatomic particles used instead of mass and charge?
|
Because their masses and charges are really small
|
|
|
What do all atoms of the same element have?
|
The same number of neutrons
|
|
|
What are isotopes?
|
Isotopes of an element are atoms with the same number of protons but a different number of neutrons, eg Cl-35 & Cl-37
|
|
|
What decides the chemical properties of an element?
|
The number and arrangement of the electrons.
|
|
|
Why do Isotopes have the same chemical properties?
|
Because isotopes have the same configuration of electrons
|
|
|
Why do isotopes of an element have slightly different physical properties?
|
Isotopes have slightly different physical properties, such as different densities, rates of diffusion, exit...because physical properties often depend more on the mass of the atom.
|
|
|
Define relative atomic mass, Ar.
|
Relative atomic mass is the average mass of an atom of an element, on a scale where an atom of carbon-12 is 12.
|
|
|
Define relative atomic mass, Ar.
|
Relative atomic mass is the average mass of an atom of an element, on a scale where an atom of carbon-12 is 12.
|
|
|
Define relative isotopic mass.
|
Relative isotopic mass is the mass of an atom of an isotope of an element on a scale where an atom of carbon 12 is 12.
|
|
|
Define relative atomic mass, Ar.
|
Relative atomic mass is the average mass of an atom of an element, on a scale where an atom of carbon-12 is 12.
|
|
|
Define relative isotopic mass.
|
Relative isotopic mass is the mass of an atom of an isotope of an element on a scale where an atom of carbon 12 is 12.
|
|
|
Define relative molecular (relative formula mass), Mr.
|
The average mass of a molecule or formula unit on a scale where an atom of Carbon-12 is 12.
|
|
|
How can relative masses (Ar, Mr & relative isotopic mass) be measures?
|
Using a Mass Spectrometer.
|
|
|
How can relative masses (Ar, Mr & relative isotopic mass) be measures?
|
Using a Mass Spectrometer.
|
|
|
What 4 things happen when a sample is placed into a "time-of-flight" mass spectrometer?
|
1). Vaporisation-the sample is turned into a gas (vaporised) using an electrical heater.
2). Ionisation-gas particles are bombarded w/ high-energy electrons to ionise them. Electrons are knocked off the particles leaving positive ions. 3). Acceleration-the positive ions are accelerated by an electric field. 4). Detection- the time taken for the positive ions to reach the detector is measured. This depends on the ion's mass and charge- light, highly charged ions will reach the detector first, heavier ions with a smaller charge will take longer and for each sample analysed a mass spectrum is produced. |
|
|
If the sample in a mass spectrum is an element, what will each line represent?
|
If the sample in a mass spectrum is an element each line will represent a different isotope of the element.
|
|
|
If the sample in a mass spectrum is an element, what will each line represent?
|
If the sample in a mass spectrum is an element each line will represent a different isotope of the element.
|
|
|
How is a molecular ion formed?
|
A molecular ion, M+(g) is formed when the bombarding electrons remove 1 electron from the molecule. This gives the peak in the spectrum with the highest mass (furthest to the right, ignoring isotopes). The mass of M+ for the molecule.
|
|
|
If the sample in a mass spectrum is an element, what will each line represent?
|
If the sample in a mass spectrum is an element each line will represent a different isotope of the element.
|
|
|
How is a molecular ion formed?
|
A molecular ion, M+(g) is formed when the bombarding electrons remove 1 electron from the molecule. This gives the peak in the spectrum with the highest mass (furthest to the right, ignoring isotopes). The mass of M+ for the molecule.
|
|
|
What do bombarding electrons cause molecules to do?
|
Bombarding electrons cause some electrons to break up into fragments, which show up on the mass spectrum, making a fragmentation pattern, which can be used to identify molecules.
|
|
|
Define Avogadro's constant.
|
Avogadro's constant is the number of particles in 1 mole of a substance.
|
|
|
Tell me what you know about Mendeleev and the Periodic table.
|
•Mendeleev arranged the known elements in order of relative atomic mass.
•Elements w/ similar physical and chemical properties were put in the same group, eg, Li, Na and K, which are reactive metals w/ low melting points. •Then he swapped elements over if he thought they fitted better into another group based in their physical and chemical properties. Eg, iodine and tellurium. Although the relative atomic mass of tellurium is higher than iodine, their properties weren't similar to other elements in the same group, unless they were swapped over. •He left gaps for elements which he thought were undiscovered. •He made predictions about the properties of undiscovered elements. Later, his predictions were found to be very close to the actual properties, which validated his version of the periodic table in the opinion of other chemists. |
|
|
Tell me what you know about Mendeleev and the Periodic table.
|
•Mendeleev arranged the known elements in order of relative atomic mass.
•Elements w/ similar physical and chemical properties were put in the same group, eg, Li, Na and K, which are reactive metals w/ low melting points. •Then he swapped elements over if he thought they fitted better into another group based in their physical and chemical properties. Eg, iodine and tellurium. Although the relative atomic mass of tellurium is higher than iodine, their properties weren't similar to other elements in the same group, unless they were swapped over. •He left gaps for elements which he thought were undiscovered. •He made predictions about the properties of undiscovered elements. Later, his predictions were found to be very close to the actual properties, which validated his version of the periodic table in the opinion of other chemists. |
|
|
How do we now arrange the elements in the periodic table?
|
We know arrange the elements in the periodic table in order of atomic number (aka, proton number) rather than relative atomic mass.
|
|
|
When is periodicity exhibited?
|
Periodicity is exhibited when:
•There's a regular pattern in a property as you go across a period. •The regular pattern is repeated in other periods. |
|
|
When is periodicity exhibited?
|
Periodicity is exhibited when:
•There's a regular pattern in a property as you go across a period. •The regular pattern is repeated in other periods. |
|
|
Give a example of periodicity.
|
Melting and boiling point
|
|
|
When is periodicity exhibited?
|
Periodicity is exhibited when:
•There's a regular pattern in a property as you go across a period. •The regular pattern is repeated in other periods. |
|
|
Give a example of periodicity.hi
|
Melting and boiling point
|
|
|
Hi
|
Hi
|
|
|
What does the shape of a molecule depend on?
|
The shape of a molecule depends on the number of groups of electrons.
|
|
|
What does the shape of a molecule depend on?
|
The shape of a molecule depends on the number of groups of electrons.
|
|
|
What could a group of electrons be?
|
A group of electrons could be a bonding pair (a single bond), two bonding pairs (a double bond), three bonding pairs (a triple bond) or a lone pair.
|
|
|
What does the shape of a molecule depend on?
|
The shape of a molecule depends on the number of groups of electrons.
|
|
|
What could a group of electrons be?
|
A group of electrons could be a bonding pair (a single bond), two bonding pairs (a double bond), three bonding pairs (a triple bond) or a lone pair.
|
|
|
What do groups of electrons do to each other?
|
Groups of electrons repel each other.
|
|
|
What does the shape of a molecule depend on?
|
The shape of a molecule depends on the number of groups of electrons.
|
|
|
What could a group of electrons be?
|
A group of electrons could be a bonding pair (a single bond), two bonding pairs (a double bond), three bonding pairs (a triple bond) or a lone pair.
|
|
|
What do groups of electrons do to each other?
|
Groups of electrons repel each other.
|
|
|
How do groups of electrons arrange themselves?
|
Groups of electrons arrange themselves so as to be as far apart in space as possible.
|
|
|
What can occupy only one of the fixed energy levels?
|
An electron in a hydrogen atom (or any other atom) can occupy any one of the fixed energy levels.
|
|
|
Which electrons have the have the lowest energy?
|
Electrons which are closest to the nucleus, in the ground state, have the lowest energy.
|
|
|
What decreases as you move away from the nucleus?
|
The difference in the energy levels decreases as the electron moves away from the nucleus.
|
|
|
Which electrons have the have the lowest energy?
|
Electrons which are closest to the nucleus, in the ground state, have the lowest energy.
|
|
|
What decreases as you move away from the nucleus?
|
The difference in the energy levels decreases as the electron moves away from the nucleus.
|
|
|
What does an absorption spectrum seen on Earth look like?
|
An absorption spectrum seen on Earth is the spectrum of visible light with black lines corresponding to the absorption a of energy by the electrons.
|
|
|
When are absorption spectra seen from Earth?
|
Absorption spectra are seen from earth when atoms in the chromosphere around stars absorb light.
|
|
|
When are absorption spectra seen from Earth?
|
Absorption spectra are seen from earth when atoms in the chromosphere around stars absorb light.
|
|
|
How does an absorption spectra work?
|
•Electrons absorb a "photon" or package of energy.
• exited electrons move up to a higher energy level-they're promoted. Which produces the lines in an absorption spectrum. •The electromagnetic radiation absorbed by each of the hydrogen atoms has a definite frequency (v) related to the difference in energy levels. |
|
|
What does an emission spectra look like?
|
An emission spectra has a black background with coloured lines on it.
|
|
|
What does an emission spectra look like?
|
An emission spectra has a black background with coloured lines on it.
|
|
|
What is the difference between an absorption and an emission spectra?
|
•An absorption spectra is a spectrum of visible light w/ black lines corresponding to the absorption a of energy by the electrons.
Whereas.... •An emission spectrum has a black background w/ coloured lines corresponding to the emissions of energy by the electrons. |
|
|
What are the similarities in the two types of spectra?
|
•the lines are in the same position
•the lines become closer at higher frequency. |
|
|
What are the similarities in the two types of spectra?
|
•the lines are in the same position
•the lines become closer at higher frequency. |
|
|
When is an emission spectrum seen?
|
An emission spectrum is seen when a chemical burns with a coloured flame.
|
|
|
What are the similarities in the two types of spectra?
|
•the lines are in the same position
•the lines become closer at higher frequency. |
|
|
When is an emission spectrum seen?
|
An emission spectrum is seen when a chemical burns with a coloured flame.
|
|
|
How does an emission spectrum work?
|
•first the electrons absorb a "photon", of package of energy.
•Exited electrons move up to a higher energy level-they're promoted •Electrons then drop back to lower energy levels, which produces the lines in an emission spectrum. •The electromagnetic radiation emitted by each of the hydrogen atoms has a definite frequent related to the difference in energy levels by (insert formula). Since (insert traiangle E) is different for each transitions, the frequency (v) is different for each transition, and therefore do is the colour of the lines |
|
|
What happens with hydroxides as you go down the group?
|
The hydroxides become more soluble as you go down the group.
|
|
|
What happens with hydroxides as you go down the group?
|
The hydroxides become more soluble as you go down the group.
|
|
|
What happens with carbonates as you go down the group?
|
The carbonates become less soluble as you go down the group.
|
|
|
What happens with hydroxides as you go down the group?
|
The hydroxides become more soluble as you go down the group.
|
|
|
What happens with carbonates as you go down the group?
|
The carbonates become less soluble as you go down the group.
|
|
|
With hydroxides, what solutions are produced as you go down the group?
|
The solutions produced are alkaline, since they contain OH- (pH>7)
|
|
|
What happens with hydroxides as you go down the group?
|
The hydroxides become more soluble as you go down the group.
|
|
|
What happens with carbonates as you go down the group?
|
The carbonates become less soluble as you go down the group.
|
|
|
With hydroxides, what solutions are produced as you go down the group?
|
The solutions produced are alkaline, since they contain OH- (pH>7)
|
|
|
What happens with the carbonates when you heat them?
|
The carbonates undergo thermal decomposition on heating to give the metal oxide and carbon dioxide.
|
|
|
When are atoms usually most stable?
|
When they have a full outer shell of electrons
|
|
|
What happens with hydroxides as you go down the group?
|
The hydroxides become more soluble as you go down the group.
|
|
|
What happens with carbonates as you go down the group?
|
The carbonates become less soluble as you go down the group.
|
|
|
With hydroxides, what solutions are produced as you go down the group?
|
The solutions produced are alkaline, since they contain OH- (pH>7)
|
|
|
What happens with the carbonates when you heat them?
|
The carbonates undergo thermal decomposition on heating to give the metal oxide and carbon dioxide.
|
|
|
When are atoms usually most stable?
|
When they have a full outer shell of electrons
|
|
|
Explain ionic bonding.
|
The metal atom transfers electron(s) to the non-metal atom so that all atoms end up with a full outer shell of electrons, resulting in the formation of charged ions.
|
|
|
Describe the appearance of a Giant ionic lattice.
|
The cations (positive ions) and anions (negative ions) produced are held together in a giant ionic lattice and are held together by an electrostatic attraction between them.
|
|
|
Explain covalent bonding.
|
To attain a full outer shell of electrons, the two non-metal atoms involved in a covalent bond share a pair of electrons.
|
|
|
What is a dative covalent bond?
|
When both electrons in the bond come from the same atom.
|
|
|
Describe and explain Metallic bonding.
|
The metal ions are arranges regularly in a lattice. The outer shell electrons are shared by all the ions and are said to be delocalised. Because of this the sea of electrons are free to move and conduct electricity.
|
|
|
What does the type of bond depend on?
|
The 2 atoms involved
|
