Answer:
It’s probably darker because it may have more minerals than the other soils.
Answer:
limestone+heat=marble
sandstone+heat=metaquartzite
shale+heat=quartzite
Answer:
Anode (oxidation): Cr(s) ⇒ Cr³⁺(aq) + 3 e⁻
Cathode (reduction): Ag⁺(aq) + 1 e⁻ ⇒ Ag(s)
Explanation:
Let's consider the notation of a galvanic cell.
Cr(s) | Cr³⁺(aq) || Ag⁺(aq) | Ag(s)
On the left, it is represented the anode (oxidation) and on the right, it is represented the cathode (reduction).
The half-reactions are:
Anode (oxidation): Cr(s) ⇒ Cr³⁺(aq) + 3 e⁻
Cathode (reduction): Ag⁺(aq) + 1 e⁻ ⇒ Ag(s)
To have the global reaction, we have to multiply the reduction by 3 (so the number of electrons gained and lost are the same) and add both half-reactions.
Global reaction: Cr(s) + 3 Ag⁺(aq) ⇒ Cr³⁺(aq) + 3 Ag(s)
Answer:
Density of copper = 8.9 g/cm³
The density of liquid mercury is 13.6 g/cm³ which means mercury is denser than copper so copper will float on liquid mercury.
Explanation:
Given data:
weight of copper metal = 1896 g
Dimensions of block = 8.4 cm, 5.5 cm, 4.6 cm
Density of copper = ?
Will it float to the liquid mercury = ?
Solution:
Density:
Density is equal to the mass of substance divided by its volume.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
D=m/v
D= density
m=mass
V=volume
volume of coper metal = 8.4 cm × 5.5 cm × 4.6 cm
volume of coper metal =212.52 cm³
d = 1896 g/ 212.52 cm³
d = 8.9 g/cm³
The density of liquid mercury is 13.6 g/cm³ which means mercury is denser than copper so copper will float on liquid mercury.
60 days have passed. In every 12 days the radioisotope loses half of its life. So in the first 12 days, from 160 grams it decreases to half so it becomes 80 grams. The second 12 days, from 80 grams, it decreases to half and becomes 40 g. The third 12 days, from 40 it becomes half to 20 g. The fourth 12 days, from 20 g it becomes half to 10 g. And in the fifth 12 days, from 10 g it becomes half to 5 grams. So 5 times it became half.
5 x 12 ( days)= 60 days
