Here are some rules:
1. The oxidation state of a free element (uncombined element) is zero.2. For a simple (monatomic) ion, the oxidation state is equal to the net charge on the ion.3. Hydrogen has an oxidation state of +1 and oxygen has an oxidation state of −2 when they are present in most compounds.
The oxidation number of Fe in Fe(NO3)2 is +3.
Answer:
After 5 second 25% C-15 will remain.
Explanation:
Given data:
Half life of C-15 = 2.5 sec
Original amount = 100%
Sample remain after 5 sec = ?
Solution:
Number of half lives = T elapsed / half life
Number of half lives = 5 sec / 2.5 sec
Number of half lives = 2
At time zero = 100%
At first half life = 100%/2 = 50%
At second half life = 50%/2 = 25%
Thus after 5 second 25% C-15 will remain.
Answer:
Density = 8.92 g/cm³
Explanation:
Density shows the relation of the mass and volume of a determined object. We have this deffinition:
Density = mass / volume
First of all, we calcualte the volume of the block of copper metal, with the data given:
8.4 cm . 5.5 cm . 4.6 cm = 212.52 cm³
Now we replace at the density formula:
Density = 1896 g /212.52 cm³ = 8.92 g/cm³