All categories

3 years ago

explain how fossils and other materials can tell us about the conditions of an area at the time it existed.

1 answer:

3 0

Well, if the fossil is from the sea/is an ocean animal (for example a fish) , then you can say that the land was once underwater. If the fossil is from a desert, you can say that the land was once a desert, etc.

You might be interested in

During an investigation, a student burns magnesium to form magnesium oxide. The starting mass of magnesium is measured as 21.3 g

enot [183]

Answer:

Percentage yield = 85.2%

Explanation:

Given data:

Mass of Mg = 21.3 g

Actual yield of MgO = 30.2 g

Percentage yield = ?

Solution:

Chemical equation:

2Mg + O₂ → 2MgO

Number of moles of Mg = mass/molar mass

Number of moles of Mg = 21.3 g / 24.3 g/mol

Number of moles of Mg = 0.88 mol

Now we will compare the moles of MgO with Mg.

Mg : MgO

2 : 2

0.88 : 0.88

Mass of MgO:

Mass of MgO= moles × molar mass

Mass of MgO= 0.88 mol × 40.3g/mol

Mass of MgO = 35.46 g

Actual yield of MgO = 30.2 g

Percentage yield:

Percentage yield = Actual yield/theoretical yield × 100

Percentage yield = 30.2 g/ 35.46 g × 100

Percentage yield = 85.2%

3 0

3 years ago

Butane C4 H10 (g),(mc016-1.jpgHf = –125.7), combusts in the presence of oxygen to form CO2 (g) (mc016-2.jpgHf = –393.5 kJ/mol),

Mice21 [21]

once you do all the math the answer is c

4 0

3 years ago

Read 2 more answers

I’LL MAKE YOU BRAINLIEST+ FREE POINTS

Pavel [41]

Answer:

The solution's new volume is 1.68 L

Explanation:

Dilution is the procedure to prepare a less concentrated solution from a more concentrated one, and simply consists of adding more solvent. So, in a dilution the amount of solute does not vary, but the volume of the solvent varies.

In summary, a dilution is a lower concentration solution than the original.

The way to do the calculations in a dilution is through the expression:

Ci*Vi=Cf*Vf

where C and V are concentration and volume, respectively; and the i and f subscripts indicate initial and final respectively.

In this case, being:

Ci= 7 M
Vi= 0.60 L
Cf= 2.5 M
Vf=?

Replacing:

7 M*0.60 L= 2.5 M* Vf

Solving:

$Vf=\frac{7 M*0.60 L}{2.5 M}$

Vf= 1.68 L

<u><em>The solution's new volume is 1.68 L</em></u>

4 0

3 years ago

In the process of preparing liquid air for fractional distillation, one fraction will be separated as a solid. What is the chemi

makvit [3.9K]

Answer:

carbon dioxide CO₂

Explanation:

Each gas has a characteristic boiling point. You can separate a random sample of gases by gradually cooling the sample until each component gas liquifies. Some compounds, such as CO₂ never liquify. Instead, they turn directly into solids.

3 0

2 years ago

When a molecule can occupy the same active site as the substrate, a situation called __________________ can result.

Sever21 [200]

When a molecule can occupy the same active site as the substrate, a situation called enzymes can result.

8 0

2 years ago