<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>
Explanation:
so then we would know about the reproduction system and how we are born and what happens with the cells inside the womens womb and how the sperm cell meets the egg cell and creates the egg
ADD THEM all, and then divide by four. Thats what I would do!
Answer:
21.6 g
Explanation:
The reaction that takes place is:
First we<u> convert the given masses of both reactants into moles</u>, using their <em>respective molar masses</em>:
- 9.6 g CH₄ ÷ 16 g/mol = 0.6 mol CH₄
- 64.9 g O₂ ÷ 32 g/mol = 2.03 mol O₂
0.6 moles of CH₄ would react completely with (2 * 0.6) 1.2 moles of O₂. As there are more O₂ moles than required, O₂ is the reactant in excess and CH₄ is the limiting reactant.
Now we <u>calculate how many moles of water are produced</u>, using the <em>number of moles of the limiting reactant</em>:
- 0.6 mol CH₄ *
= 1.2 mol H₂O
Finally we<u> convert 1.2 moles of water into grams</u>, using its <em>molar mass</em>:
- 1.2 mol * 18 g/mol = 21.6 g
