When you are collecting DNA, you could be looking for a few different things. A few examples could be skin cells, strands of hair, or possibly even a fingernail. Anything that comes from a person, including blood or saliva can be potential DNA that could help investigators to link a person back to a crime.
Investigators do not need a warrant for analyzing crime scenes due to the fact of the dangers of the fire. You must work quickly because accelerants tend to evaporate within days, sometimes hours. It is also important to note that finding the origin of the fire is very important, to make sure it won't be reignited. Debris is usually cleaned away quickly to ensure health and safety issues.
The point of origin of a fire is the lowest point, since fire burns upwards.
High explosive: Ignite almost instantly, like dynamite and TNT. Two different types are primary and secondary.
<em>Primary: easily ignited, very sensitive to heat and friction. often used to ignite other explosives. </em>
<em>Secondary: much less sensitive to heat and friction, might be ignited using other explosive materials. TNT and dynamite are both secondary. </em>
Low explosive: decompose slowly and include black and smokeless powder. They are the most common type of explosives, and are readily available.
Answer:
C6H15
Explanation:
First, we calculate the empirical formula as follows:
C = 41.33 g
H = 8.67 g
We convert each mass value to mole by dividing each element by its molar mass (C = 12g/mol, H = 1g/mol)
C = 41.33g ÷ 12g/mol = 3.44mol
H = 8.67g ÷ 1g/mol = 8.67mol
Next, we divide each mole value by the smallest (3.44mol)
C = 3.44mol ÷ 3.44mol = 1
H = 8.67mol ÷ 3.44mol = 2.52
We multiply this ratio by 2 to get a simple whole number ratio
C = 1 × 2 = 2
H = 2.52 × 2 = 5.04
Based on this, the whole number ratio of C and H is 2:5, hence, the empirical formula is C2H5.
The molecular mass of the compound is given as 87.18 g/mol, hence, the molecular formula is calculated as follows:
(C2H5)n = 87.18
[12(2) + 1(5)]n = 87.18
[24 + 5]n = 87.18
(29)n = 87.18
n = 87.18 ÷ 29
n = 3.006
Approximately to whole number, n = 3
Hence, the molecular formula of the compound is [C2H5]3
= C6H15
The change of the statue of liberty from copper to green is an example of a chemical change.
<h3>Physical and chemical change</h3>
A physical change does not involve the formation of new substances and the composition of the substance does not change. However, in a chemical change, a new substance is formed and the composition of the substance changes.
The statement that reflect a chemical change is;
- The Statue of Liberty’s metal tarnishes from copper to green.
Learn more about physical and chemical change: brainly.com/question/13316655
