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32 Cards in this Set
- Front
- Back
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What is the nucleus of at atom made of? |
protons and neutrons. |
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What are the relative charge and mass of electron, proton and neutron? |
electron = relative charge = -1 relative mass = 0.0005 (zero) proton = relative charge = +1 relative mass = 1 neutron = relative charge =0 relative mass = 1 |
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If a neutral atom has an atomic number of 11 and a mass number of 23 how many proton, electrons and neutron does it have? why? |
11 protons because of its atomic number and 11 electrons because they are equal. 12 neutrons because mass number is 23 and its 11 + 12. |
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why is an atom neutral? |
because it has an equal number of electrons and protons. the positive charge cancels out the negative charge. |
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what is an isotope? |
elements with the same atomic number but with different mass numbers. |
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12/6 C has six protons and six neutrons. 14/6C has six protons and a mass of 14 it has eight neutrons. what are they both? |
isotopes |
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How is the periodic table arranged and give example of how. |
it is arranged in order of increasing atomic number. If the electronic structure was 2.8.6 it has three electron shells so it is on the third row. |
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What is arranged horizontally and vertically in the periodic table? |
elements in the same group with the same number of of electrons in the outer shell are arranged vertically. elements in the same period in order of how many shells the electrons occupy are arranged horizontally. |
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Who developed the early theory of atoms? |
John Dalton and later rutherford, jj thompson and bohr found new evidence and changed the atom. |
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What makes an atom have a stable electronic structure? |
if the outer shell of eight electrons is full. |
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What is ionic bonding? |
when atoms become stable by transferring electrons. |
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What happens to metal atoms to form a stable electronic structure and what happens? |
they loose electrons. If the atom loses electrons a positive ion is formed as there are fewer negatively charged electrons than the number of positively charged protons in the nucleus. |
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What happens to non-metal atoms to form a stable electronic structure and what happens? |
they gain electrons to fill the outer shell . if an atom gains electrons a negative ion is formed because the number of negatively charged electrons is more than the number of positively charged protons in the nucleus. |
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During ionic bonding what happens between the metal atom and the non metal atom? |
The metal atom become a positive ion and the non metal atom becomes a negative ion and they're attracted to one another. |
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what happens during the ionic bonding of magnesium oxide? |
- The magnesium atom loses two electrons to form a positive magnesium ion. -oxygen atom gains two electrons to form a negative oxide ion. - these are represented through a dot cross diagram showing the two ions in brackets with the outer shell completed or left blanc if lost. - outside the bracket if lost 2 electrons 2+ because it has lost 2 but turned positive. and vice versa. |
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What are positive and negative ions held together by ? |
forces of attraction |
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What is the structure of sodium chloride and magnesium oxide is relation to conducting electricity? |
their structure is a giant ionic lattice, in which positive ions have strong electrostatic attraction to negative ions. they always exist as solids. |
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When do sodium chloride and magnesium oxide conduct electricity? |
When they're molten. |
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What are the physical properties of sodium chloride and magnesium oxide ? |
- they have high melting points as there are strong attractions between the positive and negative ions. - they do not conduct electricity when solid because the ions cannot move. - they conduct electricity when a solution or molten because the ions are free to move. |
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the melting point of MgO is higher than NaCl because? |
- there are Mg2+, not Na+ ions and 02- not Cl- ions, so there are stronger electrostatic attractions between positive and negative ions. - each magnesium atom donates two electrons to the oxygen atom, which makes a stronger bond when sodium atoms transfer one electron to chlorine atoms. -Magnesium ions are very small in radius, so magnesium can get much closer to oxygen, which makes the bonder stronger. More energy is needed to separate the ions. |
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What is covalent bonding? |
non meatballs can share electron pairs between atoms. |
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In covalent bonding what does a dot cross diagram represent? |
the formation of simple molecules that contain single and double covalent bonds can be represented by dot cross diagram which show the outer shell electrons. |
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What is an intermolecular force? |
the attraction between carbon dioxide molecules is called an intermolecular force. The attraction between water molecules is also known as an intermolecular force. |
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If a substance has low melting point how does this relate to weak molecular force? |
The weak intermolecular forces in substances that have similar structures such as carbon dioxide and water mean the the molecules are easy to break apart so the substances have low melting points. |
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if in the atom of an element has electrons in in only one occupied shell where will it be found? |
in group one metals this applied to all other groups throughout the periodic table. |
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Cesium and rubidium are both group 1 metals and have similar properties to lithium, sodium and potassium: such as? |
-they react vigorously with water. -hydrogen gas is given off. -The metal reacts with water to form an alkali the hydroxide of the metal. |
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how to you predict how an alkali metal such as caesium and rubidium will behave? |
by looking at the pattern of reactivity in other alkali metals -potassium reacts more vigorously than sodium. - sodium reacts more vigorously than lithium. In group 1 metals if we know the melting points, boiling points and electrical conductivity of sodium and potassium we can predict rubidium and caesium because they become more reactive. |
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Why do group 1 metals have similar properties? |
because they have one electron in their outer shell. |
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What is the equation for an alkali metal loosing an electron and forming a positive ion? |
Nz - e- to Na+ |
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What is the process called when electrons are lost? |
oxidisation K - e- to K+ if it is easier for the alkali metal to loose one electron it is more reactive. oxidisation is OIL oxidisation is loss |
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what can a flame test be used for? |
to see if lithium, sodium or potassium is present in the compound. |
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How can the flame test be carried out? |
wearing safety goggles - a flame test wire is moistened with dilute hydrochloric acid - the flame test wire is dipped in to the solid chemical. -the flame test wire is put in a blue bunsen burner flame. - the colours of the flames are recorded. |
