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3 years ago

Which isotope is used to date ancient artifacts such as fossils?

Chemistry

1 answer:

RideAnS [48]3 years ago

6 0

Scientists use carbon-14 to date ancient fossils.

Plants and animals absorb carbon-14 produced by cosmic rays. The ratio of C-14 to C-12 is constant when they are alive.

When they die, the C-14 decays to C-12, and the ratio changes.

Carbon-14 has a half-life of 5730 years. Thus, the object loses half its C-14 every 5730 years.

Scientists can use the C-14 to C-12 ratio to date fossils up to 70 000 years old.

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Is malachite A mineral, a rock or neuter

dybincka [34]

a malachite is a mineral

5 0

3 years ago

A sample of nitrogen is initially at a pressure of 1.7 kPa, a temperature of -10 C and a volume of 7.5 m3. Then the volume is de

zhannawk [14.2K]

Answer:

$\boxed{\text{2.6 kPa}}$

Explanation:

To solve this problem, we can use the Combined Gas Laws:

$\dfrac{p_{1}V_{1} }{T_{1}} = \dfrac{p_{2}V_{2} }{T_{2}}$

Data:

p₁ = 1.7 kPa; V₁ = 7.5 m³; T₁ = -10 °C

p₂ = ?; V₂ = 3.8 m³; T₂ = 200 K

Calculations:

(a) Convert temperature to kelvins

T₁ = (-10 + 273.15) K = 263.15 K

(b) Calculate the pressure

$\begin{array}{rcl}\dfrac{1.7 \times 7.5 }{263.15} & = & \dfrac{p_{2} \times 3.8}{200}\\\\0.0485 & = & 0.0190p_{2}\\p_{2} & = & \textbf{2.6 kPa}\\\end{array}\\\text{The new pressure of the gas is \boxed{\textbf{2.6 kPa}}}$

7 0

3 years ago

Which metal is more active than NI and less active than Zn?

Mademuasel [1]

Answer : The correct option is, (2) Cr (Chromium)

Explanation :

The reactivity series of metal are arranged of the reactivity from the highest to the lowest. Reactivity series is used to determine the products of the single displacement reactions. In the single displacement reaction, the most reactive metal displaces the least reactive metal.

From the given reactivity series we conclude that there are two metal (Mg and Cr) are more reactive metal than the Ni and there are two metal (Pb and Cr) are less reactive metal than the Zn. So, the Cr (Chromium) is the metal which is more active than Ni and less active than Zn.

Hence, the correct option is, (2) Cr

7 0

3 years ago

Read 2 more answers

Need a bit of help with this. Fill in the coefficients, explain your answer.

sp2606 [1]

Answer:

4Fe + 3O₂ → 2Fe₂O₃

General Formulas and Concepts:

Chemistry - Reactions

Balancing Reactions

Explanation:

Step 1: Define

RxN: Fe + O₂ → Fe₂O₃

Step 2: Balance

We need to balance both Fe and O.

LCM of 2 and 3 is 6:

Fe + 3O₂ → 2Fe₂O₃

We now need the same amount of Fe on both sides:

4Fe + 3O₂ → 2Fe₂O₃

4 0

3 years ago

How do clouds and precipitation form

Elza [17]

Umm, it depends on what lesson you are learning- but clouds form bc it’s so cold in the sky that the moisture forms clouds. precipitation is just water that evaporated into the clouds and the clouds hold it til they are full and then the precipitation falls

5 0

3 years ago

Read 2 more answers