The Ancient Egyptians used simple sundials and divided days into smaller parts, and it has been suggested that as early as 1,500BC, they divided the interval between sunrise and sunset into 12 parts. ... Known as a clepsydra, it uses a flow of water to measure time.
Answer:
1610.7 g is the weigh for 4.64×10²⁴ atoms of Bi
Explanation:
Let's do the required conversions:
1 mol of atoms has 6.02×10²³ atoms
Bi → 1 mol of bismuth weighs 208.98 grams
Let's do the rules of three:
6.02×10²³ atoms are the amount of 1 mol of Bi
4.64×10²⁴ atoms are contained in (4.64×10²⁴ . 1) /6.02×10²³ = 7.71 moles
1 mol of Bi weighs 208.98 g
7.71 moles of Bi must weigh (7.71 . 208.98 ) /1 = 1610.7 g
Answer:
Metallic bonding may be described as the sharing of free electrons among a lattice of positively charged metal ions. The structure of metallic bonds is very different from that of covalent and ionic bonds. ... In metallic bonds, the valence electrons from the s and p orbitals of the interacting metal atoms delocalize.
I bottle:
250 * 150mg = 37500mg
If 37500mg ------- cost ------- <span> $2.95
so 1mg ------- cost ------- x
x = 1mg*</span> $2.95 / 37500mg = $7,87*10⁻⁵
II bottle
125 * 200mg = 25000mg
If 25000mg ---------- cost ---------- <span>$3.50
so 1mg ---------- cost ---------- x
x = 1mg* </span>$3.50 / 25000mg = $0,00014=$1,4*10⁻⁴
$7,87*10⁻⁵ < $1,4*10<span>⁻⁴
</span>
1st bottle is better bargain cause 1mg of aspirin its cheaper than in 2nd.
