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4 years ago

Why are fingerprints individual evidence?

Chemistry

1 answer:

True [87]4 years ago

3 0

Because no one else can have the same fingerprint as another person. Each fingerprint is individual and unique.

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Explain why different liquids do not reach the same height in capillary tubes of the same diameter. Please choose the best expla

andrezito [222]

Answer:

c) Cohesive forces stronger than adhesive forces reduce the height of the liquid in the capillary tube, whereas adhesive forces stronger than cohesive forces increase the height of the liquid.

Explanation:

Two types of forces bring about capillary action.

One is cohesion, which is the intermolecular attraction between like molecules (that is, the liquid molecules). The second force, called adhesion, is an attraction between unlike molecules, such as those in a liquid and in the sides of a glass tube.

If adhesion is stronger than cohesion, the contents of the tube will be pulled upward. This process continues until the adhesive force is balanced by the weight of the liquid in the tube.

4 0

4 years ago

What is the density of a bar of lead that weighs 173 g and has the following dimensions: l= 2.00 cm, w = 3.00 cm, h = 1.00 in?

oksano4ka [1.4K]

Answer:

$\rho=7373.2g/cm^3$

Explanation:

Hello!

In this case, since the density is defined as the degree of compactness of a substance, and is defined as the mass over the volume:

$\rho= \frac{m}{V}$

Given the dimensions of the bar of lead, we can compute the volume as shown below:

$V=2.00cm*3.00cm*1.00in*\frac{1in}{2.54cm} \\\\V=2.36cm^3$

Thus, the density turns out:

$\rho=\frac{173g}{2.36cm^3} \\\\\rho=7373.2g/cm^3$

Best regards!

8 0

3 years ago

Which best explains how heat plays a role in the movement of materials within Earth's interior?

vfiekz [6]

Answer:

Hot material near the core is less dense and rises, when it cools, it becomes more dense and sinks.

Explanation:

This best explains how heat plays a role in the movement of materials within Earth's interior because it's how convection works. Convection is the circular motion that happens when warmer air or liquid which has faster moving molecules, making it less dense rises, while the cooler air or liquid drops down. Convection currents within the earth move layers of magma, and convection in the ocean creates currents.

3 0

4 years ago

Read 2 more answers

Please i need your help asap!

denis23 [38]

Answer:

Density is mass over volume.

Explanation:

6 0

3 years ago

How many grams of C6H6O3 will react with 97.0grams of O2? C6H6O3+3O2 ===> 6CO+3H2O

likoan [24]

Answer:

127.3 g

Explanation:

Data Given

mass of O₂= 97 g

mass of C₆H₆O₃ = ?

Reaction Given:

C₆H₆O₃ + 3O₂ --------> 6CO + 3H₂O

Solution:

First find the mass of C₆H₆O₃ from the reaction that it combine with how many grams of oxygen (O₂).

Look at the balanced reaction

C₆H₆O₃ + 3O₂ --------> 6CO + 3H₂O

1 mol 3 mol

So 1 mole of C₆H₆O₃ combine with 3 moles of O₂

Now

convert the moles into mass for which we have to know molar mass of C₆H₆O₃ and O₂

Molar mass of C₆H₆O₃

Molar mass of C₆H₆O₃ = 6(12) + 6(1) +3(16) = 72 + 6 + 48

Molar mass of C₆H₆O₃ = 126 g/mol

mass of C₆H₆O₃

mass in grams = no. of moles x molar mass

mass of C₆H₆O₃ = 1 mol x 126 g/mol

mass of C₆H₆O₃ = 126 g

Molar mass of O₂ = 2(16)

Molar mass of O₂= 32 g/mol

mass of O₂

mass in grams = no. of moles x molar mass

mass of O₂ = 3 mol x 32 g/mol

mass of O₂ = 96 g

So,

96 g of O₂ combine with 126 g of C₆H₆O₃ then how many grams of C₆H₆O₃ will combine with 97.0grams of O2

Apply unity Formula

96 g of O₂ ≅ 126 g of C₆H₆O₃

97 g of O₂ ≅ X g of C₆H₆O₃

By cross multiplication

X g of O₂ = 126 g x 97 g / 96 g

X g of O₂ = 127.3 g

127.3 g of C₆H₆O₃ will combine with 97 g of O₂

mass of C₆H₆O = 127.3 g

7 0

3 years ago