All categories

4 years ago

In the city a street peddler offers you a diamond ring for 30 bucks how can you test the rock

Chemistry

1 answer:

larisa86 [58]4 years ago

3 0

Explanation:

Hardness test — Scratch the rock with a fingernail, a copper penny, a glass plate or nail, and a ceramic plate. Check your Guide to assign it a rating on the Mohs Scale of Hardness.

Color streak test — Test for the “color streak” of the minerals by rubbing the rock across the ceramic plate in the Mineral Test Kit, or across smooth

cement. Look up which colors indicate which minerals are present.

Magnetism test — Hold the magnet in the Mineral Test Kit near your rock. If there is a magnetic pull, it has a metal mineral in it.

Acidity test — Put vinegar in the bottle included in the Mineral Test Kit. Squeeze out a few drops on the rock. If it fizzes, it contains carbonate.

A quick and easy way to find out whether your diamond is real or fake: try fogging it up with your breath. If it clears up after one or two seconds, then your diamond is real, but if it stays fogged for three to four seconds chances are that you're looking at a fake.

You might be interested in

The table describes the properties of four compounds.

Pie

Answer:

Compound B and D

Explanation:

Both are good conductors of electricity.

3 0

3 years ago

A gaseous mixture contains 434.0 Torr H 2 ( g ) , 434.0 Torr H2(g), 389.9 Torr N 2 ( g ) , 389.9 Torr N2(g), and 77.9 Torr Ar (

weqwewe [10]

Answer:

H₂: 0.48, N₂: 0.43; Ar: 0.09

Explanation:

First of all, sum all the pressures to know the total pressure in the mixture.

434 Torr + 389.9 Torr + 77.9 Torr = 901.8 Torr

Mole fraction = Pressure gas / Total Pressure

Mole Fraction H₂: 434 Torr /901.8 Torr = 0.48

Mole Fraction N₂: 389.9 /901.8 Torr =0.43

Mole Fraction Ar: 77.9 /901.8 Torr = 0.09

Remember: <u>SUM OF MOLE FRACTION = 1</u>

8 0

3 years ago

A negatively charged ion that is formed by an atom gaining one or more electrons is called a(n):

Vilka [71]

Answer:

"Anion" is correct option

Explanation:

An anion is an ion that has gained one or more electrons, acquiring a negative charge.

8 0

3 years ago

Read 2 more answers

In testing the effectiveness of an antacid compound, 20.0g of Hydrochloric Acid is mixed with 28.0g of Magnesium Hydroxide. Will

BartSMP [9]

Answer:

Base Mg(OH)2 does neutralise the acid and is 12g in excess.

Explanation:

2HCL +Mg(OH)2 -> MgCl2 + 2H20

2 * 36.458 g of HCL react with 58.319 g of Mg(OH)2 to neutralise it.

72.916 HCl reacts with 58.319 g of the base.

So 20 g HCl reacts with (58.319/72.916) * 20 = 16g.

There are 28 g of Mg(OH)2 so the base does neutralise all the acid.

The Mg(OH)2 is 28 - 16 = 12 g in excess.

4 0

3 years ago

A sample of paper from an ancient scroll was found to contain 39.5% 14C content as compared to a present-day sample. The t1/2 fo

nirvana33 [79]

Answer

7665 years

Procedure

Let N₀ be the amount of carbon-14 present in a living organism. According to the radioactive decay law, the number of carbon-14 atoms, N, left in a dead tissue sample after a certain time, t, is given by the exponential equation:

N = N₀e^(-λt)

where λ is the decay constant which is related to half-life (T1/2) by the equation:

$\lambda=\frac{ln(2)}{t_{\frac{1}{2}}}$

Here, ln(2) is the natural logarithm of 2.

The percent of carbon-14 remaining after time t is given by N/N₀.

Using the first equation, we can determine λt.

The half-life of carbon-14 is 5,720 years, thus, we can calculate λ using the second equation, and then find t.

$\lambda=\frac{ln(2)}{5720}=1.211\times10^{-4}$

Solving the second equation for t, and using the λ we have just calculated we will have

t= 7665 years

3 0

1 year ago