1) in periodic acid (HIO₄), iodine has oxidation number +7, hydrogen has oxidation number +1, oxygen has -2, compound has neutral charge:
+1 + x + 4 · (-2) = 0.
x = +7.
2) in molecule of iodine (I₂), iodine has oxidation number 0, because iodine is nonpolar molecule.
3) in sodium iodide (NaI), iodine has oxidation number -1, sodium has oxidation number +1:
+1 + x = 0.
x = -1.
4) in iodic acid (HIO₃), iodine has oxidation number +5, hydrogen has oxidation number +1, oxygen has -2, compound has neutral charge:
+1 + x + 3 · (-2) = 0.
x = +5.
<u>Answer:</u>
The principle of faunal succession state <em>"Specific groups of organisms have followed one another in a definite sequence through the Earth's history."</em>
<u>Explanation:</u>
Faunal succession basically means is that the fossils of the flora and fauna of different eras can be found in a specific order and never in the same strata. This allows the geologists to determine the time sequence and also to identify the various strata by dating the fossils that are found in each of them. The older version of fossils are found beneath the fossils of modified versions. For example fossils of simple feathers that cannot support flight are found to be succeeded by fossils of more complex feathers.
The formula is for 1 Calcium, 3 Magnesium, 4 Carbon, & 12 Oxygen. The 4 after the parenthesis of (CO3) distributes to each element.
Answer : There are 4 Carbon atoms in the formula.
The ostrich runs 21 N then goes back by 25 S
The displacement is -4 S
21 - 25 = -4
Answer:
52 da
Step-by-step explanation:
Whenever a question asks you, "How long to reach a certain concentration?" or something similar, you must use the appropriate integrated rate law expression.
The i<em>ntegrated rate law for a first-order reaction </em>is
ln([A₀]/[A] ) = kt
Data:
[A]₀ = 750 mg
[A] = 68 mg
t_ ½ = 15 da
Step 1. Calculate the value of the rate constant.
t_½ = ln2/k Multiply each side by k
kt_½ = ln2 Divide each side by t_½
k = ln2/t_½
= ln2/15
= 0.0462 da⁻¹
Step 2. Calculate the time
ln(750/68) = 0.0462t
ln11.0 = 0.0462t
2.40 = 0.0462t Divide each side by 0.0462
t = 52 da
