Answer:
Mg
Explanation:
Electronegativity increase to the right and top of the periodic table. So the element that is the most toward the left and bottom is the least electronegative.
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What is the purpose of a catalyst?
O A. To change the potential energy of the reactants
O B. To lower the activation energy of a reaction
O C. To increase the kinetic energy of the reactants
O D. To shift the equilibrium position of a reaction
Answer:
To lower the activation energy of a reaction
Explanation:
i just took the test and got it right ...... i hope this helps :)
Which one of the following reactions would produce the largest amount of heat
per mole of hydrogen?
A) C(s) + 2 H2 (g) CH4 (g) AH° = -74.9
kJ/mol
B) N2O (g) + 3 H2 (g) N2H4 (g)+ H2O (l)
AH° = -316.8 kJ/mol
C) 2 H2(g) + O2 (g) 2 H2O (l) AH° = -571.6
kJ/mol
D) N2 (g) + 3 H2 (g) 2 NH3 (g) AH° = -91.8
kJ/mol
Answer:
C) 2 H2(g) + O2 (g) 2 H2O (l) AH° = -571.6
kJ/mol
Explanation:
The magnitude of heat released in an exothermic reaction is shown by the magnitude of the change in enthalpy.
The more negative the enthalpy change of the reaction, the more the heat released by the process.
Hence, 2 H2(g) + O2 (g) 2 H2O (l) AH° = -571.6 kJ/mol has the most negative value of enthalpy change hence the greatest amount of heat is released in this reaction.
The reaction which would produce the largest amount of heat per mole of hydrogen is; Choice C: 2H2(g) + O2 (g). ===> 2 H2O (l) AH° = -571.6
AH° = -571.6kJ/mol.
According to the question;
We are required to identify the reaction which would produce the largest amount of heat per mole of hydrogen.It is evident that all the reactions are exothermic; the reactions release heat.
In essence, the reaction which produces the largest amount of heat is that with the largest negative enthalpy change, AH.In this scenario; the reaction that would produce the largest amount of heat per mole of hydrogen is Choice C: 2H2(g) + O2 (g) =====> 2 H2O (l) AH° = -571.6 kJ/mol
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How many particles are in 3.4 moles of NaCl?
Answer:
The answer is
2.049 × 10²⁴ particlesExplanation:
To find the number of entities or particles given the number of moles of a substance we use the formula
N = n × Lwhere n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question
n = 3.4 mol
We have
N = 3.4 × 6.02 × 10²³
We have the final answer as
2.049 × 10²⁴ particlesHope this helps you
Which of the following describes geothermal energy in use?
A
A drought in recent years has lowered the amount of hydroelectric power produced by the Hoover Dam.
B
The wide open land and strong gusts of the Greater Accra region in Ghana make it a perfect location for multiple turbines.
C
Iceland is situated on top of multiple volcanoes and harnesses this natural power to heat the roads and sidewalks in the winter.
D
Innovators are working to create panels to replace asphalt on highways, so roadways can generate energy from the sun even as cars burn fossil fuels.
The statement which describes geothermal energy in use is iceland is situated on top of multiple volcanoes and harnesses this natural power to heat the roads and sidewalks in the winter.
What is geothermal energy?Geothermal energy is the natural energy or we can say that renewable energy which can be used without any use of chemicals and damage of environment.
Geothermal energy is used for many purposes like hydroelectric energy, wind energy, solar energy, etc.
First and second options are not correct because in that utilization of geothermal is not mention.Iceland on the top of valconoes is used to warm up the roads and sidewalks in the winter season, this gives the importance of the geothermal energy.At the last option they are planning for the future utilization, so we will not consider that point for right now.Hence, iceland on top of volcanoes describe the use of geothermal energy.
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What are some factors that affect weather?
A. altitude, topography, and latitude
B. atm pressure, wind, and temp
C. visibility, altitude, and geography
Which scientist proposed the idea of the 'nucleus' after the unexpected results of his students’ gold foil experiment?
Group of answer choices
Democritus
Dalton
Bohr
Rutherford
Answer:
D
Explanation:
The nucleus was postulated as small and dense to account for the scattering of alpha particles from thin gold foil, as observed in a series of experiments performed by undergraduate Ernest Marsden under the direction of Rutherford and German physicist Hans Geiger in 1909.
What would be the result of adding one proton to an atom
Answer:
Protons carry a positive electrical charge and they alone determine the charge of the nucleus. Adding or removing protons from the nucleus changes the charge of the nucleus and changes that atom's atomic number. For example, adding a proton to the nucleus of an atom of hydrogen creates an atom of helium.
i hope this helps!
How many atoms of H are in 11 moles of H2O
Answer:
1.325×10²⁵
Explanation:
1 mole of H2O has 2 mole of H atom
11 mole of H20 has 22 mole of H atom
we know
1 mole=6.023×10²³ atom
hence 22mole H =22×6.023×10²³
=1.325×10²⁵
Electronegativity and ionization energy __________ from left to right within a period and __________ from top to
bottom within a group.
Answer:
C, increases/decreases
Explanation:
As you move down a group on the periodic table, the electronegativity of an element decreases because the increased number of energy levels puts the outer electrons very far away from the pull of the nucleus.
How can the knowledge of a material’s chemical makeup or use be utilized?
A. To classify minerals
B. To identify minerals
C. To determine the color of the minerals
D. To determine how to break down minerals
To identify minerals
Each material chemical makeup are a variety of chemical compounds which has each own category. They have different functional groups which helps people identify which material they look for. For instance, hydroxyl group has chemical makeup of alcohol
To identify minerals
Explanation:
Each material chemical makeup are a variety of chemical compounds which has each own category. They have different functional groups which helps people identify which material they look for. For instance, hydroxyl group has chemical makeup of alcohol
Juan fills two separate beakers with boiling water. The first beaker holds 500 mL. The second beaker only holds 75 mL. Juan then measures the temperature of both beakers and calculates how long it takes the water in each beaker to reach room temperature. Which of the following is true?
Answer:
The water in the 75 mL beaker will cool down more rapidly then the water in the 500 mL beaker.
Explanation:
The scale of an object influences the object's properties. For example, the water in a small beaker loses heat more rapidly than the water in a large beaker. This is because heat loss decreases as volume increases. As the scale of a beaker increases, its volume increases. Therefore, the larger the beaker, the slower the water inside the beaker will cool.
What is the maximum kinetic energy of an ejected electron if silver metal is irradiated with 224 nm light? The
threshold wavelength for a silver metal surface is 267 nm.
Give your answer accurate to three significant figures. Use exponential notation (e.g. 1.23e-19).
Answer:The maximum kinetic energy KEe of ejected electrons (photoelectrons) is given by KEe=hf−BE KE e = h f − BE , where hf is the photon energy and BE is the binding energy (or work function) of the electron to the particular material.
Explanation:
The maximum kinetic energy of an ejected electron if silver metal is irradiated with 224 nm light is 4.66eV.
What is kinetic energy?Kinetic energy is defined as is a form of energy that an object and particle has by the reason of its movement.
It is also defined as the measure of the work that an object does by the virtue of its motion.
Kinetic energy can be expressed as
KE = 1/2 mv²
KE = hc / ∧
KE = 6.63 x 10⁻³⁴ x 3 x 10⁸ / 267
KE = 7.45 x 10⁻¹⁹ J
The charge on electrons 1.6 x 10⁻¹⁹ C
So, Maximum kinetic energy = 7.45 x 10⁻¹⁹ / 1.6 x 10⁻¹⁹
= 4.66 eV
Thus, the maximum kinetic energy of an ejected electron if silver metal is irradiated with 224 nm light is 4.66eV.
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can someone please help me
A homogeneous mixture is:
A. composed of only one type of element.
B. composed of different parts that are indistinguishable in their color, texture, or appearance.
C. composed of different parts that are distinguishable in their color, texture, or appearance.
D. composed of atoms bonded together.
Answer: A homogeneous mixture is a solid, liquid or gaseous mixture that has the same proportions of its components throughout any given sample.
Explanation:
A homogeneous mixture is composed of different parts that are indistinguishable in their color, texture, or appearance.
What is the difference between homogenous and heterogeneous mixtures?
The extent of the elements' mixing together and the uniformity of their composition distinguish heterogeneous mixtures from homogeneous ones.
Homogenous mixtureWhen the elements that make up a combination are evenly distributed throughout the mixture, the mixture is said to be homogenous. The combination has a constant composition throughout. In a homogeneous mixture, only one phase of matter is visible at any given time. In a homogenous mixture, you would not see a liquid and a gas or a liquid and a solid.Examples: air, sugar water, steel, etc.Heterogeneous mixtureA heterogeneous mixture is one in which the constituent parts are not uniform or have discrete areas with various qualities. The various samples from the mixture differ from one another. In a heterogeneous mixture, even though two or more regions have the same state of matter, you can always distinguish between them by looking at their unique qualities.Examples: Cereal in milk, vegetable soup, blood, etc.Learn more about homogenous and heterogeneous mixtures here:
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HELP I'LL AWARD BRAINLIEST
Answer:
slope of line a: y=2x-2
slope of line b: y=2x+2
slope of line c: y=1x+2
Explanation:
hope this helps!!
Does the shape of molecule matter?
A gas has a volume of 50mL at a pressure of 2 atm. Increase the volume to 200mL, and the temperature remains constant. What is the new pressure?
Answer:
The answer is 0.5 atmExplanation:
The new pressure can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
where
P1 is the initial pressure
P2 is the final pressure
V1 is the initial volume
V2 is the final volume
Since we are finding the new pressure we have
[tex]P_2 = \frac{P_1V_1}{V_2} \\[/tex]
We have
[tex]P_2 = \frac{50 \times 2}{200} = \frac{100}{200} = \frac{1}{2} \\ [/tex]
We have the final answer as
0.5 atmHope this helps you
What is the freezing point of calcium?
Is calcium brittle?
Does calcium conduct electricity?
PLEASE IF YOU CAN HELP ME OUT AS SOON AS POSSIBLE IT WOULD BE MUCH APPRECIATED!!! THANK YOU!! :)
Which force keeps planets in orbit around the Sun?
O A. Strong nuclear force
O B. Electric force
O C. Gravity
O D. Magnetic force
Answer: Gravity
Explanation:
A PE X
Question 7 of 10
You have two pieces of metal. Metal A has a higher temperature than metal
B. What does this tell you about them?
A. The molecules in metal A are vibrating faster.
B. There is more light energy in metal B.
C. Metal B has more heat energy.
D. Metal A has more gravitational potential energy.
SUBMIT
Answer:
Answer is A.
Explanation:
13.Surface tension is a property of
A. liquids, only
B. solids, only
С.gases and solids
D.gases and liquids
Answer:
I think it is liquid's only.
Explanation:
Answer:
Liquids only i am not sure but i think its A
A compound is found to contain 40.05 % sulfur and 59.95 % oxygen by mass.
The empirical formula for this compound is
Answer:
im not good at chem
Explanation:
sorry bro
The empirical formula for the compound containing 40.05 % sulfur and 59.95 % oxygen is SO₃
Data obtained from the question Sulphur (S) = 40.05%Oxygen (O) = 59.95%Empirical formula =? How to determine the empirical formulaThe empirical formula of the compound can be obtained as follow
Divide by their molar mass
S = 40.05 / 32 = 1.25
O = 59.95 / 16 = 3.75
Divide by the smallest
S = 1.25 / 1.25 = 1
O = 3.75 / 1.25 = 3
Thus, the empirical formula of the compound is SO₃
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What volume of hydrogen is formed when 3.00 g of
magnesium react with an excess of dilute sulfuric acid is
carried out under room temperature and pressure at 1 atm.
Answer:
Volume of hydrogen gas formed = 3.1 L
Explanation:
Given data:
Mass of magnesium = 3.00 g
Temperature = room = 27°C (27+273 = 300 K)
Pressure = 1 atm
Volume of hydrogen gas formed = ?
Solution:
Chemical equation:
Mg + H₂SO₄ → MgSO₄ + H₂
Number of moles of Mg:
Number of moles = mass/molar mass
Number of moles = 3.00 g/ 24 g/mol
Number of moles = 0.125 mol
Now we will compare the moles Mg with hydrogen.
Mg : H₂
1 : 1
0.125 : 0.125
Volume of hydrogen:
PV = nRT
1 atm × V = 0.125 mol × 0.0821 atm.L /K.mol × 300 k
V = 3.1atm.L/1 atm
V = 3.1 L
a
Select the correct answer.
In which of these examples does chemical energy change to electrical energy?
A. digesting food
B. photosynthesis
O C. respiration
D. using a battery
Reset
Next
Answer:
D. Using a battery
Answer:
I hope this helps
Explanation:
Which of these does not accurately describe the Wright brothers' first
airplane?
A. It had wings that flapped,similar to birds wings
B.it had powerful yet exceptionally lightweight engines
C.it was created after various designs were tested in a wind tunnel
D.it was created using the engineering process
Answer: A
Explanation:
it had wings that flapped, similar to birds' wings.
How is a sand bar formed?
Answer:
Matter is classified into two broad categories, namely, pure substances and mixtures. Mixtures can be separated into pure substances by physical methods. Pure substances are further divided into categories as elements and compounds. ... A pure substance can be either an element or a compound.
Explanation:
52° 31' 12.0288"N and 13° 24' 17.8344" E.
What continent is it on?
Answer: Europe
Explanation: it’s in germany
An atom has 6 protons, 7 neutrons and 5 electrons. what element is it?
Answer:
Carbon
Explanation:
Because it was very
Calculate the number of moles in 144 g of P.