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
Oil is sucked up through wide floating heads and pumped into storage tanks. Although suction skimmers are generally very efficient, one disadvantage is that they are vulnerable to becoming clogged by debris and ice and require constant skilled observation.
The volume of a 1.86-carat diamond in cubic centimeters is 0.106 cm³
Given,
The density of a diamond is 3.513 g/cm³.
We have to find out the volume of a 1.86-carat diamond in cubic centimeters.
Convert the units of the diamond from carat to grams, we have:
(1.86 carats) x (0.200 g / 1 carat) = 0.372 g
The volume of the diamond is obtained by dividing the mass by the density, therefore using the formula, we get
v = m / d
v = 0.372 g / (3.51 g/cm³) = 0.1059 cm³
or, v = 0.106 cm³ (approx)
Therefore, the volume of a 1.86-carat diamond is approximately 0.106 cm³.
To learn more about the volume, visit: brainly.com/question/1578538
#SPJ9
