<span>All metals have similar properties BUT, there can be wide variations in melting point, boiling point, density, electrical conductivity and physical strength.<span>To explain the physical properties of metals like iron or sodium we need a more sophisticated picture than a simple particle model of atoms all lined up in close packed rows and layers, though this picture is correctly described as another example of a giant lattice held together by metallic bonding.</span><span>A giant metallic lattice – the <span>crystal lattice of metals consists of ions (NOT atoms) </span>surrounded by a 'sea of electrons' that form the giant lattice (2D diagram above right).</span><span>The outer electrons (–) from the original metal atoms are free to move around between the positive metal ions formed (+).</span><span>These 'free' or 'delocalised' electrons from the outer shell of the metal atoms are the 'electronic glue' holding the particles together.</span><span>There is a strong electrical force of attraction between these <span>free electrons </span>(mobile electrons or 'sea' of delocalised electrons)<span> (–)</span> and the 'immobile' positive metal ions (+) that form the giant lattice and this is the metallic bond. The attractive force acts in all directions.</span><span>Metallic bonding is not directional like covalent bonding, it is like ionic bonding in the sense that the force of attraction between the positive metal ions and the mobile electrons acts in every direction about the fixed (immobile) metal ions of the metal crystal lattice, but in ionic lattices none of the ions are mobile. a big difference between a metal bond and an ionic bond.</span><span>Metals can become weakened when repeatedly stressed and strained.<span><span>This can lead to faults developing in the metal structure called 'metal fatigue' or 'stress fractures'.</span><span>If the metal fatigue is significant it can lead to the collapse of a metal structure.</span></span></span></span>
Answer:
They are averages.
Explanation:
atomic numbers on periodic tables are derived from the average value of all the isotopes of the element. So being averages they are sometimes not integers.
Reactants left products right
<h3>
Answer:</h3>
52 mm
<h3>
Explanation:</h3>
We are given;
Required to convert it to cm
We are going to use the appropriate conversion factor;
- The units used to measure length include;
Kilometer(km)
10
Hectometer (Hm)
10
Decameter (dkm)
10
Meter(m)
10
Decimeter (dm)
10
Centimeter (cm)
10
Millimeter (mm)
Therefore; the appropriate conversion factor is 10mm/cm
Thus;
5.2 cm will be equivalent to;
= 5.2 cm × 10 mm/cm
= 52 mm
Therefore, the length of magnesium ribbon is 52 mm
Answer:
Increasing the concentration of the reagents makes the collision between two molecules of the reagents more likely, thereby increasing the probability that the reaction will occur between these reagents.
As for the relationship between concentration and volume, density also comes into play, a higher volume, lower molarity and also lower concentration.
The pressure when increasing could generate a closer approach between the particles, therefore generating an increase in the reaction speed.
Pressure and volume are related but inversely proportional, therefore if the volume increases the pressure decreases and so on.
the reaction rate increases as the contact surface area increases. This is due to the fact that more solid particles are exposed and can be reached by reactant molecules.
A perfect reaction where the collision is promoted and the reaction speed advances is with the presence of a solvent, with an increase in pressure and a decrease in volume, with an increase in the exposure of the surface, with the presence of a catalyst, with increasing temperature and with increasing entrance
Explanation:
The reaction rate is defined as the amount of substance that is transformed into a certain reaction per unit of volume and time. For example, the oxidation of iron under atmospheric conditions is a slow reaction that can take many years but over time it is oxidized sooner or later by the oxygenation of its surface layer, but the combustion of butane in a fire is a reaction that happens in fractions of seconds, giving rise to an exothermic reaction with products such as CO2 and H2O
