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3 years ago

What does a marine fossil in the desert tell scientists?

Chemistry

1 answer:

vredina [299]3 years ago

4 0

The correct answer is C.

There are examples of desserts that were once seas and oceans.The Tethys sea that once covered the Sahara desert retreated. Because the earth has tectonic plates that are constantly moving and shifting, places that were once oceans may be raised up high above sea level causing the sea to retreat. Marine life that once lived in the ocean and died will remain there and may be uncovered as time goes on. For this reason, if marine fossils are found in the desert it means that at some point in history, that area was once under water.

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Please help me with this question!! read the photo

pishuonlain [190]

There are 1.92 × 10^23 atoms Mo in the cylinder.

Step 1. Calculate the mass of the cylinder

Mass = 22.0 mL × (8.20 g/1 mL) = 180.4 g

Step 2. Calculate the mass of Mo

Mass of Mo = 180.4 g alloy × (17.0 g Mo/100 g alloy) = 30.67 g Mo

Step 3. Convert grams of Mo to moles of Mo

Moles of Mo = 30.67 g Mo × (1 mol Mo/95.95 g Mo) = 0.3196 mol Mo

Step 4. Convert moles of Mo to atoms of Mo

Atoms of Mo = 0.3196 mol Mo × (6.022 × 10^23 atoms Mo)/(1 mol Mo)

= 1.92 × 10^23 atoms Mo

7 0

3 years ago

The mass of an atom may be found by adding the

Darina [25.2K]

Answer:

protons and neutrons

Explanation:

5 0

3 years ago

Determine the molarity of a 6.0 mole% sulfuric acid solution with SG-a 1.07 Note: Atomic Weight: S (32), O 16); H (O)

marin [14]

Answer:

The molarity of a 6.0 mole% sulfuric acid solution is 2.8157 Molar.

Explanation:

Suppose there are 100 moles in solution:

Moles of sulfuric acid = 6% of 100 moles = 6 moles

Mass of 6 moles of sulfuric acid = 6 mol × 98 g/mol=588 g

Moles of water = 100%- 6% = 94%= 94 moles

Mass of water = 94 mol × 18 g/mol = 1692 g

Specific gravity of the solution ,S.G= 1.07

Density of solution = D

$S.G=\frac{D}{d_w}$

$d_w$ = density of water = 1 g/mL

$D=S.G\times d_w=1.07\times 1 g/mL=1.07 g/mL$

Mass of the solution = 588 g + 1692 g = 2280 g

Volume of the solution = V

Volume = $\frac{Mass}{Density}$

$=\frac{2280 g}{1.07 g/mL}=2130.84 mL=2.13084 L$

1 mL = 0.001 L

$Molarity = \frac{n}{V(L)}$

n = number of moles of compound

V = volume of the solution in L

here we have ,n = 6 moles of sulfuric acid

V = 2.13084 L

So, the molarity of the solution is :

$Molarity=\frac{6 mol}{2.13084 L}=2.8157 mol/L$

5 0

3 years ago

Atoms of arsenic (As) are often added to silicon (Si) in a process called doping to change the conductivity of the silicon. How

IRINA_888 [86]

Answer:

d) An atom of arsenic has one more valence electron and more electron shells than an atom of silicon, so the conductivity increases because the arsenic atom loses the electron.

Explanation:

This is an example of a n-type semiconductor. The additional electron introduced to the 'grid' of silicon atoms causes an increase in the conductivity of the silicon. This additional electron is introduced as arsenic loses its extra electron.

5 0

3 years ago

Read 2 more answers

Sulfur dioxide gas (SO2) and oxygen gas (O2) react to form the liquid product of sulfur trioxide (SO3). How much sulfur dioxide

taurus [48]

1) Balanced chemical equation:

2SO2 (g) + O2 (g) -> 2SO3 (l)

2) Molar ratios

2 mol SO2 : 1 mol O2 : 2 mol SO3

3) Convert 6.00 g O2 to moles

number of moles = mass in grams / molar mass

number of moles = 6.00 g / 32 g/mol = 0.1875 mol O2.

4) Use proportions with the molar ratios

=> 2 moles SO2 / 1 mol O2 = x / 0.1875 mol O2

=> x = 0.1875 mol O2 * 2 mol SO2 / 1 mol O2 = 0.375 mol SO2.

5) Convert 0.375 mol SO2 to grams

mass in grams = number of moles * molar mass

molar mass SO2 = 32 g/mol + 2*16 g/mol = 64 g/mol

=> mass SO2 = 0.375 mol * 64 g / mol = 24.0 g

Answer: 24.0 g of SO2 are needed to react completely with 6.00 g O2.

7 0

3 years ago