Parrallax is used to calculate the distance.
<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:
5727 years or 5730 (rounded to match 3 sig figs) whichever one your teacher prefers
Explanation:
First Order decay has a half life formula of Half Life = Ln (2) / k = 0.693/K
Half-life = 0.693/k = 0.693/1.21 x10-4 = 5727 years or 5730 (rounded to match 3 sig figs)
This should be correct because if you google the half-life of 14 C it is ~ 5700 years
Explanation:
When iodine heptafluoride reacts rapidly with water to give a mixture of periodic acid and hydrofluoric acid. Reaction equation for the same is as follows.

As it is given that there are
moles of iodine heptafluoride are present. Molar mass of
is 259.9 g/mol. Molar mass of
is 227.94 g/mol and molar mass of HF is 20.01 g/mol.
Now, according to the reaction equation
M
gives
M
.
Also, the volume is given as 795 ml or 0.795 L (as 1 mL = 0.001 L).
Hence, calculate the concentration of
into the solution as follows.
Concentration = 
= 
=
mol/L
or, = 0.047 M
Now, as 1 mol of
produces 7 mol HF. So,
M HF.
Therefore, concentration of HF will be calculated as follows.
Concentration of HF = 
= 0.33 M
Thus, we can conclude that concentration of periodic acid is 0.047 M and concentration of hydrofluoric acid is 0.33 M.
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