Which term is defined as the sum of protons and neutrons in an atom.
Answer:
Mass number
Explanation:
1
This question is about the Earth and its atmosphere.
Figure 1 shows the Earth and its atmosphere billions of years ago.
The boiling point of water is 100°C.
Suggest one reason why there was no liquid water on the Earth's surface billions of
years ago.
Earth's early
atmosphere of:
• carbon dioxide
• water vapour
• methane
• ammonia
Answer:
water vapour
Explanation:
allow the Earth’s surface
temperature was too/very hot
or water evaporated/ boiled
or turned to steam/gas
allow because of heat from
volcanoes
ignore the Earth’s surface
was covered by volcanoes
ignore water turned to water
vapour
6. 0.465 mole sample of gas exerts 4.43 atm of pressure in a 2.25 L container. What is the temperature of the gas in the container?
Answer:
T = 262KExplanation:
n = 0.465
P = 4.43 atm
V = 2.25 L
T = ?
Follow this equation below
PV = nRT4.43 x 2.25 = 0.465 x 0.08206 x T
9.97 = 0.038 x T
(Dividing both sides by 0.038 to get rid of it)
T = 262K or you could say 262.4K
Hope this helps!!
Imagine a campfire on a cold day. At first, the temperature of each log is as cold as the air around it. A few hours after the fire has burned out, the temperature of the ashes will also be cold. But in between, when the fire is burning, the temperature of the logs and surrounding air is very hot. What is the source of this thermal energy? For the answer, begin by identifying the reactants and products for the overall chemical reaction of burning wood. Wood is mostly carbohydrates, the bulk of which is cellulose. Cellulose is made up of hundreds to thousands of glucose groups connectected by oxygen molecules. The chemical formula for cellulose is (C6H12O6)n, where n is the number of glucose groups. For more manageable models, carbohydrates will be modelled as glucose with a chemical formula of C6H12O6.
Answer:
See explanation
Explanation:
According to the first law of thermodynamics, energy can neither be created nor destroyed, but can be transformed from one form to another.
The thermal energy observed in the hot air while the fire rages is obtained from the chemical energy stored in carbohydrates(cellulose) that compose the wood material. As the wood is burnt, this chemical energy stored in chemical bonds of the wood material is converted to heat. The chemical reaction in the combustion of wood can be simply modeled as the combustion of n moles of glucose.
nC6H12O6(s) + 6nO2(g) ===> 6nCO2(g) + 6nH2O(g)
Note that n may even be thousands of glucose molecules that combine to form cellulose present in wood.
A student dissolves 73 g of sodium nitrate, NaNO3, in 100 mL of water and observes a clear, colorless
solution. The student begins to add more sodium nitrate to the solution and it instantly becomes a cloudy,
heterogeneous mixture. The original solution the student prepared is best described as
unsaturated
saturated
immiscible.
supersaturated
Describe the changes in membrane permeability that occur at the point of stimulation on the axon.
Answer:
The permeability of a membrane is affected by temperature, the types of solutes present and the level of cell hydration. Increasing temperature makes the membrane more unstable and very fluid.
Explanation:
How many moles of molecular oxygen will be needed for
the complete combustion of 100.0 g of sulfur dioxide? The product of this reaction
is sulfur trioxide.
A. 0.7804 moles
B. 1.561 moles
C. 0.641 moles
D. 1.281 moles
Answer:
The answer is A. 0.7804 moles
whats the biggest thing in the whole universe
Answer:
The biggest thing in the universe is a supercluster known in the universe is the Hercules-Corona Borealis Great Wall.
Explanation:
When any reversible reaction is at equilibrium, what conditions are necessarily true?.
Answer:
Reversible reactions that happen in a closed system eventually reach equilibrium. At equilibrium, the concentrations of reactants and products do not change. But the forward and reverse reactions have not stopped - they are still going on, and at the same rate as each other.
When any reversible reaction is at equilibrium, the conditions are necessarily true are the amount of reactant and products stops changing, and the rate of forward reaction equals rate of backward reaction. The correct options are B and D.
What is a reversible reaction?A reversible reaction occurs when the conversion of reactants to products and the conversion of products to reactants occur at the same time.
A and B can react to form C and D, or C and D can react to form A and B in the reverse reaction. In thermodynamics, this is not the same as a reversible process.
In a closed system, reversible reactions eventually reach equilibrium. The concentrations of both reactants and products remain constant at equilibrium.
But the forward and reverse reactions have not stopped; they are still occurring at the same rate.
Reversible reactions continue until equilibrium is reached, which means that the amounts of reactant and product are balanced.
Thus, the correct options are B and D.
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Your question seems incomplete, the missing options are attached below as image:
A mercury lamp emits radiation with a wavelength of 4. 36x 105 cm. A. What is this wavelength in meters?
18 points ! Kinetic Molecular Theory has to do with
A. the identity of gas particles.
B. the pressure of gas particles.
C. the motion of gas particles.
D. the volume of gas particles.
Answer:
C. the motion of gas particles.
Explanation:
The kinetic molecular theory is a simple but very effective model that effectively explains ideal gas behavior. The theory assumes that gases consist of widely separated molecules of negligible volume that are in constant motion, colliding elastically with one another and the walls of their container with average velocities determined by their absolute temperatures.
A 1 kg object accelerates at a rate of 5 m/s2.
Answer:
5 N.
Explanation:
We can calculate the net force on the object by using Newton's second law of motion:
F is the net force on an object
m is the mass of the object
a is its acceleration
For the object in this problem, we have
m = 1 kg is its mass
is its acceleration
Substituting into the equation, we find the net force:
reaction of ethene with H2
Answer:
The hydrogenation of ethene
Ethene reacts with hydrogen in the presence of a finely divided nickel catalyst at a temperature of about 150°C. Ethane is produced. This is a fairly pointless reaction because ethene is a far more useful compound than ethane!
Explanation:
Write 483,928 in each form.
Word:
Expanded:
4) What type of reaction is the following?
exothermic
endothermic
not enough information given
Answer:
Endothermic
Explanation:
Notice that heat is written as part of the reactants. Therefore, heat is necessary for the reaction to proceed.
In other words, the reaction is endothermic.
Conversely, if the heat is written as part of the products, heat is released as the reaction proceeds and hence the reaction is exothermic.
A chemist wants to extract copper metal from copper chloride solution. The chemist places 1.50 grams of aluminum foil in a solution of 14 grams of copper (II) chloride. A single replacement reaction takes place. What best explains the state of the reaction mixture after the reaction?
Unbalanced equation: CuCl2 + Al → AlCl3 + Cu (4 points)
Group of answer choices
Less than 6.0 grams of copper is formed, and some aluminum is left in the reaction mixture.
More than 6.5 grams of copper is formed, and some aluminum is left in the reaction mixture.
Less than 6.0 grams of copper is formed, and some copper chloride is left in the reaction mixture.
More than 6.5 grams of copper is formed, and some copper chloride is left in the reaction mixture.
Less than 6.0 grams of copper is formed, and some aluminum is left in the reaction mixture
Stoichiometric calculationsFrom the equation of the reaction:
3CuCl2 + 2Al → 2AlCl3 + 3Cu
Mole ratio of CuCl2 and Al = 3:2
Mole of 1.5 g aluminum foil = 1.5/26.98
= 0.06 moles
Mole of 14 g CuCl2 = 14/134.45
= 0.10 moles
For every 3 moles of CuCl2, 2 mole of Al is needed.
Thus, for 0.10 moles of CuCl2, the mole of Al needed would be:
0.10 x 2/3 = 0.07 moles
CuCl2 is, thus, slightly in excess while Al is the limiting reagent.
Mole ratio of Al and Cu = 2:3
For 0.06 mole Al, the mole of Cu will be: 0.06x3/2 = 0.09 moles
Mass of 0.09 moles Cu = 0.09 x 63.55
= 5.71 g
Thus, less than 6.0 grams Cu is formed while a little CuCl2 would be left in the reaction mixture.
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80+80
help
pelase
80+2-0
Answer:
the first one would be 160 and the second 82 :)
Explanation:
Answer:
160 and 82?
Explanation:
80 plus itself is 160 and 80 plus 2 is 82 minus 0 is 82.
hello people ~
Which of the following groups contain only synthetic fibres?
A. Nylon, Terylene, Wool
B. Cotton, Polycot, Rayon
C. PVC, Polythene, Bakelite
D. Acrylic, Silk, Wool
Answer:
PVC,polythene,Bakelite
Explanation:
PVC stands for polyvinyl chloride used in pipes Polythene used as bags.Bakelite used in switchesArrange the missing steps in the correct order.
Answer:
There's nothing to arrange l
Which statement best describes one rule for determining the relative age of a rock layers
Which of the following properties of pure solvents increase when a solute is added?
a. Freezing point
b. Vapor pressure
c. Boiling point
d. Cohesion
Question
Write the correct skeleton equation for the following:
fluorine gas reacts with calcium metal to form
solid calcium fluoride
Let's see
Fluorine reacts with Calcium metal to form calcium fluoride
[tex]\\ \rm\rightarrowtail Flourine+Calcium\longrightarrow CaF_2[/tex]
Write states[tex]\\ \rm\rightarrowtail Fluorine(g)+Calcium (s)\longrightarrow Calcium\: Fluoride (s)[/tex]
The chemical equation when fluorine gas reacts with calcium metal to form solid calcium fluoride is Ca + F₂[tex]\rightarrow[/tex] CaF₂.
What is chemical equation?Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.
A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .
The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.
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Read this excerpt from the play An Adventure for Detective Dennis:
Stars twinkle in the windows of the library.
What element of a play is shown in this text?
Cast of characters
Dialogue
Scene
Setting description
Answer:
the answer is Scene
Explanation:
because it is describing the atmosphere of where the book/play is taking place
Answer:
the answer is Scene
Explanation:
What is the specific heat of titanium if the temperature of a 36.7 g sample of titanium is increases by
4.8 °C when 91.6 J of heat is added?
Answer:
what is the initial temperature? i can answer once I know. if it doesnt say, then I dont know and I'll delete this
Can someone please help me? :(
Answer:
B and D
Explanation:
They collect equal amounts.of solar energy
Answer:
The answer is
C. B and D
Explanation:
The equator is where there is the most solar energy
B and D are symmetrical over the equator.
How does stoichiometry support the law of conservation of mass?
A It compares the mass of the reactants to the number of moles of reactants.
B It compares the mass of each reactant to the mass of each product.
C It compares the mass of the products to the number of atoms in the products.
D It compares the mass of the products to the mass of the reactants. ***
The stoichiometry supports the law of conservation of mass by comparing the mass of the products to the mass of the reactants.
What is stoichiometry?Stoichiometry is the measurement of the reactant and product of a reaction.
It is found in the law of conservation of mass, which says that the mass of the reactant is equal to the mass of the product.
Due to stoichiometry, if the mass of the product is known then, the mass of the reactant can be known.
Thus, the correct option is D.
Learn more about stoichiometry
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1. Why is sodium kept immersed in keroscne oil?
Explanation:
Sodium and Potassium are highly reactive metals and react vigorously with the oxygen, carbon dioxide and moisture present in the air such that it may even cause a fire. To prevent this explosive reaction, Sodium iskept immersed in kerosene becauseSodium doesn't react with kerosene
Which of these statements accurately describes polymers?
Polymers are macromolecules.
Polymers are simple molecules.
Polymers are made of metal atoms.
Polymers contain double bonds.
Answer:
Its A.) Polymers are macromolecules
Explanation:
Answer:
The correct answer that you are looking for is A.) Polymers are macromolecules.
how many grams of baf2 are in 3.7 moles of baf2
To convert moles to gram multiply 3.7 moles of BaF2 to the molar mass of BaF2
BaF2 molar mass = 175.326
3.7 moles x 175.326g = 648.70g BaF2
How many copper atoms are in a pure copper statue with a mass of 198 kg?
Answer:
No.of copper atoms= no.of moles x No x atomicity
(No - avagardro's number )
= wt / atomic mass x No x 1
= 198 x 10 ^3 g / 63.5 x No
= 3.118 x 10^3 x 6.02 x 10^23
= 18.77 x 10^26 atoms.