Ask question

Ask question

All categories

grandymaker [24]

3 years ago

10

Scientists discover remains of wooden structures near a Celtic runes site. What kind of testing will indicate when the stones we

re moved into place by the Celts?
Carbon dating

Radioactive dating

1 answer:

stepladder [879]3 years ago

6 0

Answer:

Carbon

Explanation:

Bc i got this question on my test

You might be interested in

Why do we need an isolated system for the law of conservation of mass to be true?

Alex_Xolod [135]

Answer:

The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.

7 0

3 years ago

Read 2 more answers

A certain amount of gas at 25 C and at a pressure of 0.800 atm is contained in a glass vessel. Suppose that the vessel can with

sp2606 [1]

Answer:

=745 Kelvin

Explanation:

According to the pressure law the relationship between the pressure and absolute temperature of a gas at a constant volume is directly proportional.
An increase in temperature causes a corresponding increase in pressure at a constant volume.

That is;

$P\alpha T$

Mathematically;

$P = kT\\(Constant)k =\frac{P}{T} \\$

When there are two varying conditions;

$\frac{P1}{T1} =\frac{P2}{T2}$

In this case;

P1 = 0.8 atm

T1 = 25+273 = 298 K

P2 =2.00 atm

T2= ?

Therefore;

$T2= \frac{P2T1}{P1}$

$T2= \frac{(2)(298)}{0.8}$

$= 745 K$

Therefore, the temperature can be raised up to 745 kelvin without bursting vessel.

8 0

3 years ago

Read 2 more answers

How much carbon dioxide is released when it is fully combusted with 4Kg of ethanol with more than enough oxygen? How do you work

Karolina [17]

Answer:

7.640 kg

Explanation:

Step 1: Write the balanced complete combustion equation for ethanol

C₂H₆O + 3 O₂ ⇒ 2 CO₂ + 3 H₂O

Step 2: Calculate the moles corresponding to 4 kg (4000 g) of C₂H₆O

The molar mass of C₂H₆O is 46.07 g/mol.

4000 g × 1 mol/46.07 g = 86.82 mol

Step 3: Calculate the moles of CO₂ released

86.82 mol C₂H₆O × 2 mol CO₂/1 mol C₂H₆O = 173.6 mol CO₂

Step 4: Calculate the mass corresponding to 173.6 moles of CO₂

The molar mass of CO₂ is 44.01 g/mol.

173.6 mol × 44.01 g/mol = 7640 g = 7.640 kg

5 0

3 years ago

Liquid nitrogen, which has a boiling point of −195.79°C, is used as a coolant and as a preservative for biological tissues. Is t

Ray Of Light [21]

Answer:

Explanation:

Entropy is measure of disorder so as we lower the temperature of gas , its entropy decreases .

Hence at - 200°C entropy of nitrogen will be less than that at - 190°C .

At freezing point ,

entropy of fusion = latent heat / freezing temperature

= .71 kJ / ( 273 - 210 )

= 710 / 63 J mol⁻¹ K⁻¹ .

= 11.27 J mol⁻¹ K⁻¹ .

entropy of fusion = 11.27 J mol⁻¹ K⁻¹ .

8 0

3 years ago

The discharge of chromate ions (CrO42-) to sewers or natural waters is of concern because of both its ecological impacts and its

muminat

Answer:

45727g

Explanation:

So, have the overall ionic equation given as the following;

CrO42^- + 3 Fe2^+ + 8 H2O ------> Cr(OH)^3(s) + 3 Fe(OH)^3(s) + 4 H^+.

So, we have (from the question) that the amount or quantity of the waste stream daily = 60m^3/h, and the waste stream daily contains waste stream containing = 4.0 mg/L Cr, and the discharge limit = 0.1 mg/L.

Step one: convert m^3/ h to L/h. Therefore, 60 m^3/h × 1000dm^3 = 60000 L/h .

Step two: Determine or calculate the the value of Cr used up.

The value of Car used up ={ 60,000 × ( 4.0 - 0.1) } ÷ 1000 = 234 g.

Step three: Determine or calculate the mass of Cr(OH)3 and the mass of Fe(OH)3.

The number of moles of Cr = 234/52 = 4.5 moles.

Molar mass of Cr(OH)3 = 103 g/mol and the molar mass of Fe(OH)3 = 106.8 g/mol.

Thus, the mass of Cr(OH)3 = 4.5 × 103 = 463.5 g.

And the mass of Fe(OH)3 = 13.5 × 106.8 = 1441.8 g.

Hence, the total = 463.5 g + 1441.8 g = 1905.3 g.

Step four: Determine or calculate the How much particulate matter would be generated daily.

The amount of the particulate that would be generated daily = 24 × 1905.3 = 45727g.

7 0

3 years ago