THIS IS THE COMPLETE QUESTION BELOW
46.9 gram sample of a substance has a volume of about 3.5 centimeters3. It is solid at a room temperature of 23ºC. Out of the four substances whose properties are given, which is the most likely identity of this substance?
Substance Density (g/cm3) Melting Point (°C) Boiling Point (°C)
molybdenum 10.28 2,623 4,639
mercury 13.53 -39 357
hafnium 13.31 2,233 4,603
lead 11.34 327 1,749
A.
molybdenum
B.
mercury
C.
hafnium
D.
lead
Answer :
The correct option is OPTION C.
(C) Hafnium
Explanation;:
We were given the mass of substance as (m) = 46.9 g
The Volume of substance as (V) = 3.5 Cm^3
But we know Density of substance.= Mass/it's Volume
Then Density=46.9/3.5
=13.4g/Cm^3
From the questionthe given substance is solid at room temperature, and let us take Mercury as an example , Mercury is liquid at room temperature. ThenMercury cannot be the answer.
Base on the determined density which is 13.4 and the density of Hafnium also is 13.31 g/cm3 and it is solid at room temperature. Therefore, Hafnium is the only likely element here.
Which of the following is an acid-base neutralization reaction? (1 point) Sn + 2HBr yields SnBr2 + H2 HCl + KOH yields KCl + H2O 2AlCl3 + 3Ca(OH)2 yields 2Al(OH)3 + 3CaCl2 2C2H6 +7O2 yields 4CO2 + 6H2O
Answer:
HCl + KOH ⇒ KCl + H₂O
Explanation:
Which of the following is an acid-base neutralization reaction?
Sn + 2HBr ⇒ SnBr₂ + H₂. NO. This is a single displacement reaction.
HCl + KOH ⇒ KCl + H₂O. YES. An acid reacts with a base to form salt and water.
2AlCl₃ + 3Ca(OH)₂ ⇒ 2Al(OH)₃ + 3CaCl₂. NO. This is a double dispacement reaction.
2C₂H₆ +7O₂ ⇒ 4CO₂ + 6H₂O. NO. This is a combustion reaction.
2. Bottled Italian salad dressing is an example of *
O a suspension
a colloid
a solution
O a homogeneous mixture
12g of carbon react with 32g of oxygen to produce 44g of CO2 .which chemical law do the data illustrate
Answer:
Law of constant composition
Answer:
trtytytytytytyt
Explanation:
Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below. A purple ball in the center surrounded by overlapping concentric black ovals, each with a small green ball on each of the 6 ovals. What experimental evidence led to the development of this atomic model from the one before it? A few of the positive particles aimed at a gold foil seemed to bounce back. The colors of light emitted from heated atoms had very specific energies. Experiments with water vapor showed that elements combine in specific proportions. Cathode rays were bent in the same way whenever a magnet was brought near them.
Answer:
A few of the positive particles aimed at a gold foil seemed to bounce back.
Explanation:
Rutherford's experiment took the search for the structure of the atom a step further. In this experiment, a narrow beam of alpha particles emitted from a source was used to bombard a thin gold foil.
The scattering of the alpha particles was detected by a movable ZnS screen. It was found that most of the alpha particles followed a straight path through the gold foil but some were scattered through large angles and some even scattered backwards.
Following this experiment, Rutherford decided on his planetary model of the atom in which the nucleus is at the core of the atom with electrons moving round the nucleus in orbits. Rutherford was awarded a Nobel prize for this work.
Answer:
a
Explanation:
edge 2020
All carbon ato ms have atomic number 6 but some have mass number 12 and others have mass number 14.what is a) the same b) different about the structure of these two types of carbon atoms
Answer:
a) The similarities in their structure are;
1) The two isotopes have the same number of protons in their nucleus
2) The two isotopes have the same number of electrons in their orbit
3)The basic chemical properties of the two isotopes are the same
b) The differences in their structure are;
1) The number of neutrons in their nucleus are different
6 for carbon 12 and 8 for carbon 14
2) The structure of carbon 12 is stable while the structure of carbon 14 disintegrates
3) The isotopes have different densities, therefore, different packing
Explanation:
The atomic number is the number of protons in the nucleus of an atom
The mass number is the sum or total number of protons and neutrons in an atom
Given that the atomic number of all carbon atoms = 6
The number of protons in all carbon atoms = 6
Given that some of the carbon atoms have a mass number of 12 while others have a mass number 14, we have
Therefore, the number of neutrons in some of the carbon atoms = 12 - 6 = 6
The number of neutrons in the remaining of carbon atoms = 14 - 6 = 8
Therefore the carbon atom has two isotopes including ¹²₆C and ¹⁴₆C.
Explain why the first ionisation energy of helium is
larger than that of hydrogen.
Answer
Explanation:
helium has a structure 1s² the electrons are removed from the same orbital as in case of hydrogen the electrons are closest to the nucleus the value of ionization energy of helium is much higher than hydrogen because the nucleus now has 2 proton attracting the electrons instead of 1 in case of hydrogenSuppose you see an advertisement for a video game that claims you can actually fly around inside your home while you play it. What do your scientific literacy and critical thinking skills lead you to think about that claim?
Answer:
Scientific literacy and critical thinking skills will nullify the claims made in the advertisement.
Explanation:
The claims made in the advertisement contradict the scientific laws and the person who understands the scientific theories can easily understand that. Critical thinkers may derive rational insights from a collection of facts, and distinguish between relevant and less important reasons for problem-solving or decision making. Therefore on objectively evaluating scientific theories, we conclude to a rational decision, that is the claims are false.
Use the following steps to balance the redox reaction using half-reactions. Zn(s) + Fe3+ Zn2+ + Fe(s) (unbalanced) a. Write balanced oxidation and reduction half-reactions. Indicate which is the oxidation reaction and which is the reduction reaction. (6 points) b. Balance the charge in the two half-reactions by multiplying the half-reactions by the correct multiplication factors. (4 points) c. Add the equations and simplify to get the balanced equation.
Answer:
Explanation:
a )
Zn = Zn²⁺ + 2e ( oxidation reaction )
Fe³⁺ + 3e = Fe( s ) ( reduction reaction )
b )
[ Zn = Zn²⁺ + 2e ] x 3
[ Fe³⁺ + 3e = Fe( s ) ] x 2
-------------------------------------------------------------------
3 Zn + 2 Fe³⁺ + 6e = 3 Zn²⁺ + 2 Fe ( s ) + 6e
3 Zn + 2 Fe³⁺ = 3 Zn²⁺ + 2 Fe ( s )
In the molecule 4H2O2 the number of hydrogen atoms is what
Answer:
Scientists
Explanation:
Scientists because they are the one who makes hypothesis.
A wittig reaction occurs when 4-methylbenzaldehyde and benzyltriphenylphosphonium chloride are stirred together at room temperature in the presence of sodium hydroxide base. Draw the major isomer produced by this reaction.
Answer:
See explanation
Explanation:
The wittig reaction is an organic reaction in which an aldehyde or a ketone reacts with a phosphonium ylide to give an alkene. This phoshonium ylide that participates in the reaction is usually generated insitu in the system by reaction of an alky or aryl triphenylphosphonium halide salt with a base(sodium hydroxide is mostly used).
In this particular reaction 4-methylbenzaldehyde and benzyltriphenylphosphonium chloride were reacted together in the presence of sodium hydroxide and the product with the structure shown in the answer was obtained as the major isomer produced in the reaction.
A compound that has a sea of delocalized electrons has what type of bonding?
Answer:
Metallic Bonding
Explanation:
Metallic Bonding
In metallic bonds, the valence electrons from the s and p orbitals of the interacting metal atoms delocalize. That is to say, instead of orbiting their respective metal atoms, they form a “sea” of electrons that surrounds the positively charged atomic nuclei of the interacting metal ions.
can you catch coronavirus from F.A.R.Ts?
Answer:
No
Explanation:
Droplets or aerosols. When an infected person coughs, sneezes, or talks, droplets or tiny particles called aerosols carry the virus into the air from their nose or mouth. Anyone who is within 6 feet of that person can breathe it into their lungs.
Airborne transmission. Research shows that the virus can live in the air for up to 3 hours. It can get into your lungs if someone who has it breathes out and you breathe that air in.
Surface transmission. Another way to catch the new coronavirus is when you touch surfaces that someone who has the virus has coughed or sneezed on. You may touch a countertop or doorknob that's contaminated and then touch your nose, mouth, or eyes. The virus can live on surfaces like plastic and stainless steel for 2 to 3 days. To stop it, clean and disinfect all counters, knobs, and other surfaces you and your family touch several times a day.
Fecal-oral. Studies also suggest that virus particles can be found in infected people's poop. But experts aren't sure whether the infection can spread through contact with an infected person's stool. If that person uses the bathroom and doesn't wash their hands, they could infect things and people that they touch.
Explain why chlorine is a gas while iodine is a solid yet both are halogens. Select one: a. Both iodine and chlorine differ in strength of metallic bonds b. Chlorine has strong inter molecular forces than iodine c. Iodine molecules are large with strong inter molecular forces than chlorine
Answer:
Chlorine has strong inter molecular forces than iodine
Explanation:
Answer:
Chlorine has strong inter molecular forces than iodine
Explanation:
I2 is a solid while Cl2 is a gas because Iodine molecules are larger and therefore experience stronger intermolecular forces.
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A star is estimated to have a mass of 2.0 x 10 ^36kg. Assuming it to be a sphere of average radius of 7.0 x 10 ^5 km. Calculate the average density of the star in g/cm^3 and in lb/ft^3
Answer:
a) 1.392 x 10^6 g/cm^3
b) 8.69 x 10^7 lb/ft^3
Explanation:
mass of the star m = 2.0 x 10^36 kg
radius of the star (assumed to be spherical) r = 7.0 x 10^5 km = 7.0 x 10^8 m
The density of substance ρ = mass/volume
The volume of the star = volume of a sphere = [tex]\frac{4}{3}\pi r^{3}[/tex]
==> V = [tex]\frac{4}{3}*3.142*(7.0*10^8)^{3}[/tex] = 1.437 x 10^27 m^3
density of the star ρ = (2.0 x 10^36)/(1.437 x 10^27) = 1.392 x 10^9 kg/m^3
in g/cm^3 = (1.392 x 10^9)/1000 = 1.392 x 10^6 g/cm^3
in lb/ft^3 = (1.392 x 10^9)/16.018 = 8.69 x 10^7 lb/ft^3
A student is reading the volume from a standard 50-mL buret identical to what you used in the lab. The bottom of the meniscus is exactly on the 20-mL line. What should she record as the correct volume
Answer:
20 mL
Explanation:
The student should record 20 mL as the correct volume.
The curved surface of a liquid that is usually observed in a buret is referred to as the meniscus. This meniscus is created as a result of the surface tension of the liquid against the walls of the buret. Hence, in order to avoid errors due to parallax, the bottom of the meniscus should be read and not the top.
Therefore, the correct volume that the student should record is 20 mL.
what is the correct electron configuration for an element with five electrons in the third energy level
[tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex] is the correct electron configuration for an element with five electrons in the third energy level.
What are elements?Elements are the simplest substances which cannot be broken down using chemical methods.
The shell nearest to the nucleus, 1n, can carry two electrons, while the next shell, 2n, can carry eight, and the third shell, 3n, can carry up to eighteen.
The third shell carries 18 electrons; 2 in a 3s orbital; 6 in three 3p orbitals; and 10 in five 3d orbitals. The fourth shell carries 32 electrons; 2 in a 4s orbital; 6 in three 4p orbitals; 10 in five 4d orbitals; and 14 in seven 4f orbitals.
The element would be phosphorus. Its electron configuration is [tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex]
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what’s the answer to this?
change the following word equations into balanced equations
a) Hydrogen + Chlorine → Hydrogen chloride.
b)Hydrogen + Nitrogen→ Ammonia
c)Aluminium + sulphuric acid → Aluminium sulphate + Hydrogen
d)Iron (3) + oxygen → iron oxide
e)Copper + sulphuric acid → Copper sulphate + water + sulphur dioxide.
Answer:
Q
Explanation:
Citrus fruits may taste sour because they are _____. acidic basic neutral too ripe
Answer:
A. acidic
Explanation:
Citrus fruits may taste sour because they are acidic. They have citric acid and ascorbic acids.
What happens when two objects when they are brought closer together The mass of both objects decrease The mass of both objects increase The gravitational force between them decreases The gravitational force between them increases
Answer:
The correct option is
The gravitational force between them increases
Explanation:
According to Newton's law of universal gravitation states that the force of attraction between two bodies is directly proportional to the product of the masses of the bodies and inversely proportional to the square of the distance of their centers from each other.
The formula for universal gravitation is given as follows;
[tex]F_{1} = F_{2} =G \times \dfrac{m_{1} \times m_{2}}{r^{2}}[/tex]
Where;
F₁, and F₂ = The gravitational forces of attraction on each mass
G = The gravitational constant
m₁ = The mass of one body
m₂ = The mass of the body
r = The distance between the centers of the two bodies
Therefore, the gravitational force of attraction on each object is inversely proportional to the as the distance between the centers of the two bodies
When the distance between the centers of the two bodies decreases, the two objects are brought closer together, the gravitational force of attraction between them increases.
Answer:
Gravitational force between two objects of masses m1/m2
Explanation:
is defined by Gm1xm2/r^2, where G is a universal constant, and r is the distance between the masses. This shows you why B is wrong; it would increase. Also, A is not a good choice, as shown. In the case of B, it would increase by say, 2/1 to 4/1 by doubling ones mass. In C's case the bottom would decrease on the fraction alot (square) if they were moved closer, thus the force would be greater.
Explanation:
in other words the answer is The gravitational force between them increases
what is the relative formula mass of phosphate (PO4)? (To the nearest tenth) A. 187.9 grams B. 46.9 grams C. 23.0 grams D. 94.9 grams
Answer:
[tex]\huge\boxed{94.9\ grams}[/tex]
Explanation:
Relative formula mass of phosphate:
=> [tex]PO_{4}[/tex] [Ignoring the charge on it]
Atomic mass of P = 31.0 grams, O = 15.9 grams
=> 30.97 + 4(15.9)
=> 30.97 + 63.9
=> 94.87
≈ 94.9 grams [To nearest tenth]
Answer:
[tex]\huge \boxed{\mathrm{D. \ 94.9 \ grams}}[/tex]
Explanation:
Phosphate chemical formula is given as,
[tex]\sf PO_4[/tex]
There is one phosphorus atom and four oxygen atoms.
Atomic mass of Phosphorus [tex]\sf P[/tex] = 30.974 grams
Atomic mass of Oxygen [tex]\sf O[/tex] = 15.999 grams
[tex]\Rightarrow 30.974 + 4(15.999)[/tex]
[tex]\Rightarrow 30.974+ 63.996[/tex]
[tex]\Rightarrow 94.97[/tex]
The relative formula mass of phosphate [tex]\sf PO_4[/tex] is 94.9 grams.
Consider two bulbs seperated by a valce. Both bulbs are amintained at the same temperature. Assume that when the valve between the two bulbs is closed, the gases are sealed in their respective bulbs. When the valve is closed, the following data apply:
Bulb A Bulb B
Gas Ne CO
V 2.50L 2.00L
P 1.09 atm 0.73 atm
Assuming no temperature change, determine the final pressure inside the system after the valve connecting the two bulbs is opened. Ignore the volume of the tube connecting the two bulbs.
Answer:
The pressure is [tex]P_f = 0.93 \ atm[/tex]
Explanation:
From the question we are told that
The volume of Ne is [tex]V_N = 2.50 \ L[/tex]
The volume of CO is [tex]V_C = 2.00 \ L[/tex]
The pressure of [tex]Ne[/tex] is [tex]P_N = 1.09 \ atm[/tex]
The pressure of CO is [tex]P_C = 0.773 \ atm[/tex]
The number of moles of Ne present is evaluated using the ideal gas equation as
[tex]n_N = \frac{P_N * V_N}{R T}[/tex]
=> [tex]n_N = \frac{1.09 * 2.50 }{R T} = \frac{2.725}{RT}[/tex]
The number of moles of CO present is evaluated using the ideal gas equation as
[tex]n_N = \frac{P_C * V_C}{R T}[/tex]
=> [tex]n_N = \frac{0.73 * 2.00 }{R T} = \frac{1.46}{RT}[/tex]
The total number of moles of gas present is evaluated as
[tex]n_T = n_N + n_C[/tex]
[tex]n_T = \frac{2.725}{RT} + \frac{1.46}{RT}[/tex]
[tex]n_T = \frac{4.185}{RT}[/tex]
The total volume of gas present when valve is opened is mathematically represented as
[tex]V_T = V_N + V_C[/tex]
=> [tex]V_T = 2.50 + 2.00 = 4.50 \ L[/tex]
So
From the ideal gas equation the final pressure inside the system is mathematically represented as
[tex]P_f = \frac{n_T * RT }{ V_T}[/tex]
=> [tex]P_f = \frac{[\frac{4.185}{RT} ] * RT }{ 4.50}[/tex]
=> [tex]P_f = 0.93 \ atm[/tex]
Tips for memorizing the first 20 elements of the periodic table?
Answer:
hydrant flying with balloon, balloon has lithp letting air out, bee: really yum balloon
= = = =
hydrogen helium lithium beryllium
be bore on the balloon, balloon pops, hydrant drops and makes a car bomb
= =
boron carbon
night row general gets hurt by car bomb nearby, that general gets off boat
=
nitrogen
wearing oxygen mask, mask is full of fluride gel, then he got neon teeth
= = =
oxygen fluorine neon
(try making a story out of the elements, use your imagenation)
I will give u tips to learn whole periodic table
1. Break down the table into sections
2. Spread out the memorisation process
3. Learn the elements in a song
4. Make none sense words made from element symbols
5. Use colour to learn element groups
6. Use mnemonic device to help remember the order of elements
I am sure this will be helpful for uuu
Explanation:
find the empirical formula of the compound containing 11.3% of carbon, 43.4 % of sodium 45.3 % of oxygen
Answer:
CNa203
Explanation:
thats is method in the picture send
What is the complete ionic equation for this reaction?
2KOH(aq) + H2SO4(aq) → 2H20(1) + K2SO4(aq)
O A. 2K+ + OH + H2SO4 → OH + 2H+ + K2SO4
B. OH + 2H+ + 2H20()
C. 2KOH + H2SO4 → 2H20 + K2SO4
D. 2K+ + OH + 2H+ + SO42- → 2H20() + 2K+ + SO42-
SUBMIT
Answer:
The answer is "Option D".
Explanation:
The entire ionic equation for all the substances, which are ionic compounds but are available in an aquatic is represented in the form with ions in the full ionic equation.
In the Net ionic equation, it doesn't have the particulate matter throughout the net ionic equations throughout the equations.
In the Spectator ions, it doesn't participate in interactions mostly on reaction and the material hand. From both sides, the very same ions are present.
The evenly balanced chemical formula is,
[tex]2KOH (aq)+ H_2SO_4(aq) \longrightarrow 2H_2O(l) + K_2SO_4[/tex]
It is the separate organic compound that full ion formula will match the choice D.
If 25.0 g of carbon monoxide react with 8.50 g of ammonia and 10.0 g of hydrogen to produce water and acetonitrile (CH3CN), what mass of each excess reactant is left over after the reaction is complete?
Answer:
The mass of NH₃ left over = 0.91 g of NH₃
The mass of H₂ left over = 8.2 g of H₂
Explanation:
The given information are;
The mass of the carbon monoxide present in the reaction = 25.0 g
The mass of the ammonia present in the reaction = 8.50 g
The mass of the hydrogen present in the reaction = 10.0 g
The above masses reacts to produce water and acetonitrile (CH₃CN)
The balanced chemical equation for the reaction is given as follows;
2CO + NH₃ + 2H₂ → CH₃CN + 2H₂O
Therefore, two moles of CO reacts with one mole of NH₃ and two moles of H₂ to produce one mole of CH₃CN and two moles of H₂O
The molar mass of CO = 28.01 g/mol
The molar mass of NH₃ = 17.031 g/mol
The molar mass of H₂ = 2.0159 g/mol
The molar mass of H₂O = 18.015 g/mol
The molar mass of CH₃CN = 41.05 g/mol
The number of moles of CO present = 25/28.01 = 0.893 moles
The number of moles of NH₃ present = 8.5/17.031 = 0.5 moles
The number of moles of H₂ present = 10/2.0159 = 4.96 moles
Therefore, 0.893 moles of CO reacts with 0.893/2 mole of NH₃ and 0.893 moles of H₂ to produce 0.893/2 mole of CH₃CN and 0.893 moles of H₂O
The excess reactants left are;
0.5 - 0.893/2 = 0.0535 moles of NH₃ with mass 0.0535 × 17.031 = 0.91 g
4.96 - 0.893 = 4.067 moles of H₂ with mass 4.067 × 2.0159 = 8.2 g
The mass of NH₃ left over = 0.91 g of NH₃
The mass of H₂ left over = 8.2 g of H₂.
Select the correct answer. Which state of matter is highly compressible, is made of particles moving independently of each other, and is present in large quantities near Earth's surface? A. solid B. liquid C. gas D. plasma
Si se usa 450 gramos de carbonato de calcio para dicho proceso ¿Qué volumen de CO2 se obtendrá, si la presión es de 8 atm y la temperatura 200°C? R=0,082 atm.L/mol.K
Respuesta:
21.8 L
Explicación:
Paso 1: Escribir la reacción balanceada
CaCO₃ ⇒ CaO + CO₂
Paso 2: Convertir 450 g de CaCO₃ a moles
La masa molar de CaCO₃ es 100.09 g.
450 g × (1 mol/100.09 g) = 4.50 mol
Paso 3: Calcular los moles de CO₂ que se forman a partir de 4.50 moles de CaCO₃
La relación molar de CaCO₃ a CO₂ es 1:1. Los moles de CO₂ formados son 1/1 × 4.50 mol = 4.50 mol.
Paso 4: Convertir la temperatura a Kelvin
Usaremos la siguiente expresión.
K = °C + 273.15 = 200°C + 273.15 = 473 K
Paso 5: Calcular el volumen de CO₂
Usaremos la ecuación del gas ideal.
P × V = n × R × T
V = n × R × T / P
V = 4.50 mol × (0.082 atm.L/mol.K) × 473 K / 8 atm
V = 21.8 L
Drag each tile to the correct image. Match each hydrocarbon class to its structure. carboxylic acid amine halocarbon alcohol
Answer:
1. Amine.
2. Alcohol.
3. Carboxylic Acid.
4. Halocarbon.
Explanation:
The correct answer according to the tile are Amine, Alcohol, Carboxylic acid, Halocarbon.
How can hydrocarbons be classified based on their structure?
Hydrocarbons can be classified as either aromatic or aliphatic compounds, depending on the presence of a benzene ring.
What is the most common classification of hydrocarbons?
Alkanes are hydrocarbons in which all of the bonds are single bonds. Alkenes are hydrocarbons that contain a carbon-carbon double bond.
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Which scientist developed a new model of planetary motion?
Answer: Johannes Kepler
Answer:
i believe the answer us kepler
Explanation:
