Döbereiner grouped the known elements into <em>triads</em> (sets of three) so that
• The <em>atomic mass of the middle element</em> was approximately the average of the other two
• The <em>chemical properties of the middle element</em> were between those of the other two
• The <em>physical properties of the middle element</em> were between those of the other two
One example of a triad is Li – Na – K.
(a) Atomic mass of Na = 23.0 u
Average atomic mass of Li and K = (6.9 u + 39.1 u)/2 = 46.0 u/2 = 23.0 u
(b) Li reacts slowly with water. Na reacts rapidly. Potassium reacts violently.
(c) Melting point of Na = 371 °C.
Average melting point of Li and K = (454 °C + 330 °C)/2 = 784 °C/2
= 392 °C
<span>By definition, the first ionization energy is the energy required to remove the most loosely held electron from one mole of gaseous atoms to produce 1 mole of gaseous ions each with a charge of 1+. </span><span />
Answer:
So 1 mole
Explanation:
PV = nRT
P = Pressure atm
V = Volume L
n = Moles
R = 0.08206 L·atm·mol−1·K−1.
T = Temperature K
standard temperature = 273K
standard pressure = 1 atm
22.4 liters of oxygen
Ok so we have
V = 22.4
P = 1 atm
PV = nRT
n = PV/RT
n = 22.4/(0.08206 x 273)
n = 22.4/22.40
n = 1 mole
A conductor is what helps heat or electricity pass through an object. Examples of conductors are, silver, iron, aluminum, etc..
An insulator does the opposite and instead, stops either from going through. Examples of an insulator is paper, wood, rubber, etc.
You can use a graduated cylinder.
