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Annette [7]
3 years ago
11

How many atoms are in a 0.50 g sample of helium

Chemistry
1 answer:
Mrac [35]3 years ago
3 0
0.5 G is your answer for this question
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What is carbon? What does it do?
Archy [21]

Answer:

Carbon is in carbon dioxide, which is a greenhouse gas that works to trap heat close to Earth. Carbon is the chemical backbone of life on Earth. Carbon compounds regulate the Earth's temperature, make up the food that sustains us, and provide energy that fuels our global economy. Most of Earth's carbon is stored in rocks and sediments. The rest is located in the ocean, atmosphere, and in living organisms

Explanation:

Hope it helps. Can you give me BRAINLIEST ANSWER. Thank you

7 0
2 years ago
Prediction for Scandium (II) and Cl
SCORPION-xisa [38]

Answer:

(a) Eka-aluminum and gallium are two names of the same element as Eka-Aluminium has almost exactly the same properties as the actual properties of the gallium element. The properties: atomic mass, density, melting point, formula of chloride and formula of oxide are almost the same.

Explanation:

Scandium - Eka boron.

      (ii) Gallium - Eka aluminium.

      (iii) Germanium - Eka silicon.

3 0
2 years ago
CAM plants function using crassulacean acid metabolism. Like C4 plants, CAM plants provide preparatory step for the Calvin cycle
poizon [28]

Answer: ORGANIC ACIDS  

Explanation:

CAM PLANTS CARBOXYLATE ORGANICS ACIDS through the addition of  CO2 to PEP Carboxylase(  a phosphoenolpyruvate carboxylase enzyme present in the mesophyll cells of the cytoplasm in a green plant) to produce Oxaloacetate (organic compound).

CO2 + PEP  ⇒ C4H4O5 (oxaloacetate)

Oxaloacetate is then converted to a similar molecule, Malate (C4H6O5,  another form of organic compound) that can be transported in to the bundle-sheath cells. Malate enters the plasmodesmata and releases the CO2. The CO2 then fixed by rubisco and made into sugars via the Calvin cycle.

6 0
3 years ago
Plate movement is thought to be the result of what ​
Zielflug [23.3K]

Answer: Plate movement is thought to be driven by a combination of the motion of the seafloor away from spreading ridges due to variations in topography and density changes in the crust.

Hope this helps

7 0
3 years ago
Promethium-147 is sometimes used in luminescent paint. It has a half-life of 956.3 days. If 250 grams (g) of promethium-147 is u
Fantom [35]

Answer:

% = 76.75%

Explanation:

To solve this problem, we just need to use the expressions of half life and it's relation with the concentration or mass of a compound. That expression is the following:

A = A₀ e^(-kt)   (1)

Where:

A and A₀: concentrations or mass of the compounds, (final and initial)

k: constant decay of the compound

t: given time

Now to get the value of k, we should use the following expression:

k = ln2 / t₁/₂   (2)

You should note that this expression is valid when the reaction is of order 1 or first order. In this kind of exercises, we can assume it's a first order because we are not using the isotope for a reaction.

Now, let's calculate k:

k = ln2 / 956.3

k = 7.25x10⁻⁴ d⁻¹

With this value, we just replace it in (1) to get the final mass of the isotope. The given time is 1 year or 365 days so:

A = 250 e^(-7.25x10⁻⁴ * 365)

A = 250 e^(-0.7675)

A = 191.87 g

However, the question is the percentage left after 1 year so:

% = (191.87 / 250) * 100

<h2>% = 76.75%</h2><h2>And this is the % of isotope after 1 year</h2>
3 0
3 years ago
Read 2 more answers
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