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2 years ago

Imagine you are a detective examining a crime scene. You are trying to

Chemistry

2 answers:

Sidana [21]2 years ago

4 0

Answer:

C. pieces of hair found at the crime scene.

Explanation:

using the pieces of hair, you can get the DNA of the person. This will give u a better lead in solving the crime.

Hope it helps u ....

sveta [45]2 years ago

3 0

Answer:

C. Pieces of hair found at the crime scene.

Explanation:

Pieces of hair found at the crime scene is more useful to find the criminal who committed the crime, because it helps in indetifying criminal's DNA through the process of DNA fingerprinting. The hair is analyzed by the chemical makeup of the hair and extracting DNA from the hair follicle, pieces of hair must have hair follicle attached to find DNA of the criminal.

Nuclear DNA can be successfully extracted from the hair root. Cut hair samples are useless without hair follicle attached. Its DNA will be useful only few months for testing. The DNA last in hairs about 1,000 to 10,000 years.

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A certain metal fluoride crystallizes in such a way that the fluoride ions occupy simple cubic lattice sites, while the metal io

Bezzdna [24]

Answer:

$MF_2$

Explanation:

In a simple cubic lattice lattice, the atoms are present at the eight corners of the cibe.

Since it is mentioned that the fluorine is present at the corners and also 1 corners are shared by 8 unit cells. So, share of atom in one unit cell is:- $8\times \frac{1}{8}=1$

Also, the metal, M occupy half of the body centre. A cube has only one body centre. So, share of M in each unit cell:- $\frac{1}{2}$

Thus, the formula is:-

$M_{\frac{1}{2}}F$ Or simplifying $MF_2$

3 0

2 years ago

1. What are small-scale techniques in chemistry? <br>

stira [4]

Answer:Small-scale technique means a small quantity of chemicals that contribute to the safety of the experiments. Instead of using big beaker of chemical, micro scale technique utilize small quantities of chemical and scaled-down science equipment.

Explanation:

4 0

1 year ago

If water’s density is 1.0 g/mL, then would the perfume be more or less dense than water? Would the perfume float on top or sink

Alex17521 [72]

Answer:

usually the perfumes are made of aromatic hydrocarbons invloving

cetone, ethanol, benzaldehyde, formaldehyde, limonene, methylene chloride, camphor, ethyl acetate, linalool and benzyl alcohol. which have density lower than the water hence they will float on the top of the water.

Hope this helps you

Explanation:

5 0

1 year ago

Alka‑Seltzer is marketed as a remedy for stomach problems, such as heartburn or indigestion, and pain relief. It contains aspiri

Papessa [141]

Answer:

The equation for the reaction of one sodium bicarbonate ( NaHCO3 ) molecule with one citric acid (C6H8O7) molecule is the following:

Sodium Bicarbonate + Citric Acid ⇒ Water + Carbon Dioxide + Sodium Citrate

NaHCO3 + C6H8O7 ⇒ 3 CO2 + 3 H2O + Na3C6H5O7

Explanation:

The reaction is in balance, that is, the whole H2CO3 is not finished, but a little bit of this acid is left in the solution. Therefore, when sodium bicarbonate is added to the solution with citric acid, sodium citrate salt (C6H5O7Na3) and carbonic acid (H2CO3) are formed, which is rapidly broken down into water (H2O) and carbonic oxide (CO2).

C6H8O7 + NaHCO3 ⇒ C6H5O7Na3 + 3 H2CO3

C6H5O7Na3 + 3 H2CO3 ⇔ C6H5O7Na3 + 3 H2O + 3 CO2

5 0

1 year ago

A 23.74-mL volume of 0.0981 M NaOH was used to titrate 25.0 mL of a weak monoprotic acid solution to the stoi- chiometric point.

Dmitrij [34]

Answer:

Molar concentration of the weak acid solution is 0.0932

Explanation:

Using the formula: $\frac{C_aV_a}{C_bV+b} = \frac{n_a}{n_b}$

Where Ca = molarity of acid

Cb = molarity of base = 0.0981 M

Va = volume of acid = 25.0 mL

Vb = volume of base = 23.74 mL

na = mole of acid

nb = mole of base

Since the acid is monopromatic, 1 mole of the acid will require 1 mole of NaOH. Hence, na = nb = 1

Therefore, $C_a = \frac{C_bV_b}{V_a}$

Ca = 0.0981 x 23.74/25.0

= 0.093155 M

To 4 significant figure = 0.0932 M

3 0

1 year ago

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