Answer:
amount of He = (7.91 × 10^22) ÷ (6.02 × 10^23) = 0.131mol (3sf)
Explanation:
you make use of the mole concept formula
amount(mol) = number of particles ÷ 6.02 × 10^23
(6.02 × 10^23 is the avogadro constant, which is an extremely important number in this formula for mole concept)
Questions
1. How would you describe life and why?
a compound consists of 81.8% C and 18.2% H by mass. What is its empirical formula?
Answer:
Empirical formula of 81.8 carbon and 18.2 hydrogen
Steps
Find the empirical formula of a compound that has 81.8% of Carbon (C), 18.2% of Hydrogen (H).Divide by fractional component of each mole value: C=1.5354936431103, H=4.0709872862205Round to closest whole numbers: C=2, H=4 Combine to get the empirical formula: C2H4What is the mass of 2409793.03 particles of N2?
Shonda’s car gets an average of LaTeX: 27 miles per gallon. Gas costs $LaTeX: 2.25 per gallon and she drives LaTeX: 892 miles to get from Baltimore, MD to Orlando, FL. What are the conversion factors she could use to calculate the cost of gas to get from Baltimore to Orlando? How much will she spend on gas?
The conversion factors she could use to calculate the cost of gas : 33.037 gallon from Baltimore to Orlando
She will spend $74.33 on gas
Further explanationGiven
Shonda’s car : 27 miles per gallon
Gas cost = $ 2.25/gallon
Distance Baltimore to Orlando = 892 miles
Required
Cost of gas
Solution
Total gallon needed to get from Baltimore to Orlando :
892 miles : 27 miles/gallon = 33.037 gallon
Cost of gas :
33.037 gallon x $2.25/gallon = $74.33
What happened to your heart rate? What does the increased heart rate tell us about the circulatory system? Why do you think the circulatory system was pumping blood faster when you were running?
Pls help ill give brainliest
Which of the following is an example of a precipitate?
A: liquid evaporating into gas
B: a solid formed from a frozen liquid
C: a chunky solid formed from two liquids combining
D: a liquid solution that contains two substances
Write the chief ore of sodium and potassium respectively?
Answer:
K-sylvite
Na-rock salt
Explanation:
Sylvite is a colourless or white mineral consisting of potassium chloride, occurring typically as cubic crystals(Oxford dictionary). It is the primary ore of potassium metal. It appears colorless, sometimes with a shade of red.
Rock salt is a primary ore of sodium. It is found in rocks, seas etc. Rock salt is sometimes commonly called halite. It usually appears white in colour and is rich in sodium.
Question 18 (5 points)
(03.06 MC)
Which statement is true about oxygen and rocks? (5 points)
a
Both are mixtures.
Both are pure substances.
Oxygen is a mixture and a rock is a pure substance.
d
Oxygen is a pure substance and rocks are mixtures.
Answer:
d. oxygen is a pure substance and rocks are mixtures
Answer:
A rock is a mixture and oxygen is a pure substance
Explanation:
Oxygen is just O O O O O O and rocks have many things in it like minerals, fossils and rock stuff. I'm not a geologist
On any given day or night, what determines the visible phase of the moon
A. how much of the sunlit side of the moon is visible
B. the time of day or night that we look at the moon
C. how far the moon has rotated on its axis
D. how much of the moon is lit by the sun
Answer:
i think the answer is D if not its A
An example of a high explosive is what?
Answer:
High explosives do not need to be contained to make their bang. Nitroglycerine, trinitrotoluene, and RDX are high explosives.
Explanation:
You push 100kg door with force of 200 with what force does the door push back on you
Answer:
for every action there is equal and oposite reaction so door als pushes us back with same force. ie;200N.
PLEASE HELP ME! The question is on the image! It’s about the mole
What is the balanced equation for the manufacture of ethanol from glucose
Answer:
C6H12O6 → 2C2H5OH + 2CO2
Explanation:
Glucose is an organic molecule, specifically a sugar, with the formula C612O6 while ethanol is another organic molecule with formula; C2H5OH.
However, as rightly said in this question, ethanol can be got from glucose via a process called fermentation in the presence of a catalyst called YEAST. The balanced equation is as follows:
C6H12O6 → 2C2H5OH + 2CO2
1. __N2 + __H2-> __NH3
2. __Fe + __HCl-> __H2 + __FeCl3
Answer:
N2+ 3H2－> 2NH3
2Fe + 6HCl －> 3H2 + 2FeCl3
A student is drinking a cup of hot chocolate as they sit by a campfire on a chilly evening. They know that the cup of hot chocolate transfers thermal energy to the surrounding air. The heated air over their cup of hot chocolate expands and rises and is replaced by cooler, denser air.
This method of energy transfer is —
Answer:
A student is drinking a cup of hot chocolate as they sit by a campfire on a chilly evening. They know that the cup of hot chocolate transfers thermal energy to the surrounding air. The heated air over their cup of hot chocolate expands and rises and is replaced by cooler, denser air.
This method of energy transfer is
Explanation:
Answer:
radiation
Explanation:
radiation is when an existing heat source spreads heat to its surroundings
What are two types of matter are pure substances
Answer:
Elements and compounds are two types of pure substances.
Explanation:
what is 1/4 of 12 pleas i need help
Answer:
3
Explanation:
It's basically saying what number goes into 12 four times, I think.
9. How long will it take 120 grams of Strontium-90 to decay to 7.5 grams?
with steps pls
Answer:
116 years
Explanation:
To solve this, we will use the half life equation;
A(t) = A_o(½)^(t/t_½)
Where;
A(t) is the amount of strontium left after t years;
A_o is the initial quantity of strontium that will undergo decay;
t_½ is the half-life of strontium
t is the time it will take to decay
We are given;
A(t) = 7.5 g
A_o = 120 g
From online values, half life of strontium-90 is 29 years. Thus, t_½ = 29
Thus;
7.5 = 120 × ½^(t/29)
Divide both sides by 120 to get;
7.5/120 = ½^(t/29)
0.0625 = ½^(t/29)
In 0.0625 = (t/29) In ½
-2.772589 = (t/29) × (-0.693147)
(t/29) = -2.772589/(-0.693147)
t/29 = 4
t = 29 × 4
t = 116 years
a sample of an unknown metal has a mass of 21.6g and volume of an 8.00cm3 calculate the density of the unknown metal
Answer:
2.70 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question we have
[tex]density = \frac{21.6}{8} \\ = 2.7[/tex]
We have the final answer as
2.70 g/cm³Hope this helps you
2C3H7OH + 9O2 --> 6CO2 + 8H2O
Determine the number of grams of CO2 produced from the reaction of 5.55 moles of C3H7OH?
a
1466 g
b
16.7 g
c
367 g
d
12.2 g
e
733 g
Please show work
Answer 12.2g is the answer
PLEASE HELP I'M BEING TIMED!! Which type of star system has the most stars?
A. Open Cluster
B. globular cluster
C. Eclipsing binary
D. binary star system
Answer:
Hi! It's B - globular cluster
Answer:
B Globular Cluster
Explanation:
Sorry if I am wrong :)
chemistry between people is the stongest like mine and urs right?
Answer:
..sure....
Explanation:
Answer:
hmm i dont see it homie sike gimmi that bootiy
Most of the carbon in the rocks that form Earth's mantle and crust was stored there when Earth formed. The rest of Earth's carbon is stored and exchanged in many ways.In a model of the carbon cycle, which process does NOT contribute directly to the storage of carbon within sediment?
Answer:
Photosynthesis.
Explanation:
In photosynthesis process, carbondioxide gas enters into plant leaves from which plant produces organic molecules such as glucose. This glucose helps the plant to increase it growth and complete development stages and finally the plant dies and buried in the soil so due to decomposition process, the carbon present in the plant body releases in the soil and become part of sediments. So indirectly photosynthesis process provides carbon to the soil.
when 45mL of 0.25mol/L sulfuric acid is mixed w/ 25mL of 0.58mol/L Calcium hydroxide, the solution has a?
What is a part's structure related to?
Balance the chemical reaction for the combustion of methanol by adding the correct coefficients below
__CH3OH +__O2(little box)__CO2 +__H2O
Answer:
[tex]2~CH_3OH+3~O_2\rightarrow2~CO_2+4~H_2O\\[/tex]
The coefficients would be 2, 3, 2, and 4.
Explanation:
If we want to check this we would multiply the coefficient by each element. What we want is to have the same number of atoms on each side.
Reactant side:
# of carbon atoms: 2# of hydrogen atoms: 8# of oxygen atoms: 8Product side:
# of carbon atoms: 2# of hydrogen atoms: 8# of oxygen atoms: 8And that's it!
Please help!!! I'll give brainliest to the most helpful answer
please this is due today and I have no idea :// 3
Solve and use correct sig figs AND units: (Example of how to type: 3.26 m2)
The density of mercury is 13.6 g/mL. What is the mass of 3,426 mL of mercury?
Answer:
m = 46593.6 g
Explanation:
Given data:
Mass of mercury = ?
Volume of mercury = 3426 mL
Density of mercury = 13.6 g/mL
Solution:
Formula:
d = m/v
d = density
m = mass
v = volume
by putting values,
13.6 g/mL = m/ 3426 mL
m = 13.6 g/mL × 3426 mL
m = 46593.6 g
Complete the sentence. Select all that apply. A beta particle: is electromagnetic energy is emitted from the nucleus has zero charge has a +2 charge has a -1 charge is an electron
Answer: has a -1 charge
is an electron
is emitted from the nucleus
Explanation:
The beta particle is basically an electron with -1 charge and no mass.
Beta particles are fast-moving electron emitted by radioactive decay of substances. Beta particles have a charge of - 1, and a mass of about [tex]\frac{1}{2000}[/tex] th of a proton. This means that beta particles are the same as an electron.
A beta particle, also called beta ray or beta radiation [tex](\beta)[/tex], is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay.
A beta particle is emitted from an atomic nucleus, transforming the original nuclide to an isobar of that nuclide.
Which particle diagram represents a mixture?
( i hope you can read it)
The diagram of the mixture is the third diagram
Explanation:
A substance that only has one kind of atom is known as an element.The element cannot be broken down further into simple substances by any physical means.A substance that only has more than one kind of atom is known as a compound.The compound can be broken down further into simple substances by chemical means.The compound has a fixed proportion of atoms of different elements.A substance that only has more than one kind of element or compound is known as a mixture.The mixture can be separated by physical means.So, from this, we can conclude that from the given particle diagrams, the diagram of the mixture is the third diagram as it has one compound molecule and two atoms of a different element.
Learn more about element, compound, and mixture here:
brainly.com/question/184321?referrer=searchResults
brainly.com/question/1844804?referrer=searchResults