Answer:
Atomic number = 25 protons
Mass number = ( 25 + 30 ) = 55
name the gas which is formed when coal is heated in the absense of air
Answer:
Coke
Explanation:
A solid fuel formed by heating coal in the absence of air is coke. Coke is black colored, tough porous substance. It is pure carbon.
What is a reaction rate
Answer:
Explanation:
A reaction rate is the measure of the change in concentration of the disappearance of reactants or the change in concentration of the appearance of products per unit time
5. Which choice best represents the relationship between wavelength and frequency?
when frequency decreases, wavelength decreases
there is no relationship
when frequency increases, wavelength increases
O when frequency decreases, wavelength increases
Joelle is a manager at a construction company, and she is interested in the chemistry behind the materials they use. She has begun studying the materials used to fill walls. She knows that to keep the temperature inside a room steady the material must be a thermal insulator, and she predicts that materials should not be acidic or else they would dissolve too easily in water. Which of these is a molecular ingredient that could be used in a wall-filling material ?
Answer: C6H6
Explanation:
The molecular formula C₆H₆ represents Benzene. Benzene is colorless, flammable, and has a sweet and gasoline-like odor. It's a toxic chemical, and can cause cancer.
Benzene is a hydrocarbon and used for the manufacturing of products such as plastic, detergents, glues, dyes, and rubber. It can also be used in making wall-filling material.
Answer: C6H6
Explanation:
The molecular formula C₆H₆ represents Benzene. Benzene is colorless, flammable, and has a sweet and gasoline-like odor. It's a toxic chemical, and can cause cancer.
Benzene is a hydrocarbon and used for the manufacturing of products such as plastic, detergents, glues, dyes, and rubber. It can also be used in making wall-filling material.
Explain and describe how the photoelectric effect occurs on an atomic level in terms of protons, neutrons, and electrons
ANSWER:
Explaining the experiments on the photoelectric effect. How these experiments led to the idea if light behaving as a particle of energy called a photon.
A solution of ammonia NH3(aq) is at equilibrium. How would the equilibrium
change if NH4+ were added to the solution?
Answer: The equilibrium will shift in the direction of [tex]NH_3[/tex]
Explanation:
The chemical equation for the aqueous solution of ammonia follows:
[tex]NH_3+H_2O\rightleftharpoons NH_4^++OH^-[/tex]
According to Le-chtelier's principle:
If there is any change in the variables of the reaction, then the equilibrium will shift in that direction of equilibrium to minimize the effect.
If we add more amount of [tex]NH_4^+[/tex] to the solution, more of the products will be present. But according to Le-chtelier's principle, to minimize this effect, the equilibrium will shift in the backward direction that in the direction of [tex]NH_3[/tex]
Hence, the equilibrium will shift in the direction of [tex]NH_3[/tex]
Our solar system is more than _________ in diameter.
Answer: 287.46 billion km
Explanation: calculated it myself. nah but thats the answer
What type of nuclear decay is shown by the reaction below?
A. Alpha
B. Gamma
C. Beta
O D. Fission
Answer:
C. Beta
Explanation:
Help please I’ll give you brainless
Answer:
Step 9
Explanation:
The reason i selected step 9, is if you take a look at the picture hes setting up a funnel,With filter paper and if you take a look at number ''9'' questions it says set up a funnel, filter paper and filter flask which is shown in the picture on top that's how i got my answer
SOMEONE HELP ASAP I NEED TO FIND AN ANSWER
Answer:
A) Q + XZ = X + QZ is a single displacement reaction.
B) Q + Z = QZ is a synthesis reaction
C) QT = Q + T is a decomposition reaction
D) QT + XZ = QZ + XT is double replacement reaction.
Explanation:
A) Q + XZ = X + QZ
This is a single displacement reaction because it is one in which one element is substituted for another one in a compound. In this case X is substituted for Q.
B) Q + Z = QZ
This is a synthesis reaction because Q and z combine to form a single product QZ.
C) QT = Q + T
This is a decomposition reaction because the compound QT breaks down to form 2 simpler substances Q and T.
D) QT + XZ = QZ + XT
Thus is a double replacement reaction because QT and XZ have exchanged cations to form new compounds QZ and XT
Select the correct answer.
A sample taken from a layer of mica in a canyon has 2.10 grams of potassium-40. A test reveals it to be 2.6 billion years old. How much
potassium-40 was in the sample originally if the half-life of potassium-40 is 1.3 billion years?
O A.
4.20 g
O B.
8.40 g
O C.
12.6 g
• D.
16.8 g
O E.
25.2 g
Answer:
8.36 g
Explanation:
From;
0.693/t1/2 = 2.303/t log (No/N)
t1/2 = half life of potassium-40
t = age of the sample
No= initial amount of the sample
N= amount of the sample at time t
Substituting values;
0.693/1.3 × 10^9 = 2.303/2.6 × 10^9 log (No/2.10)
5.33 × 10^-10 = 8.86 × 10^-10 log (No/2.10)
5.33 × 10^-10/8.86 × 10^-10 = log (No/2.10)
0.6 = log (No/2.10)
Antilog (0.6) = (No/2.10)
No = 2.10 × Antilog (0.6)
No= 8.36 g
If no loss or gain of electrons occur by mixing of two atoms, we say that they may be attached to each
other due to
A proton attraction
B neutron attraction
C sharing of electrons
D opposite charges
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Answer:
The correct option is option C
Explanation:
Loss or gain of electron(s) occurs in a type of attraction known as electrovalent or ionic attraction. In this type, there is transfer (or loss) of electron(s) from a metal atom to become positively charged while a nonmetal accepts (or gains) this electron to become negatively charged.
When this does not happen, two metal atoms can become attached by sharing the same electrons through a form of attraction known as covalent bonding. Here, the two atoms share electrons (known as shared pair) together to achieve there octet configuration on the outermost shell.
what is the change of state from gas to liquid
Vapourization and condensation. the actual 1 shud be vapourization.
los metales se oxidan
304 cm x m and 67kg to gram please helpppp!!!!!!!!
Answer:
[tex]304cm = 3.04m \\ 67kg = 67000g[/tex]
Explanation:
[tex]100cm \: = 1m \\ 304cm = x \\ use \: \: cross \: multipication \\ 100x = 304 \\ \frac{100x}{100} = \frac{304}{100} \\ x = 3.04m[/tex]
-------------------------------------------------
[tex]1kg = 1000g \\ 67kg = x \\ \\ use \: cross \: \: multipication \\ 1x = 67 \times 1000 \\ x = 67000g[/tex]
Hope this helps
Have a nice day!
Sodium is less reactive than potassium.
Answer:
Sodium atoms due to being smaller in size have high ionization energy and thus, it can't lose electrons easily and is more stable and less reactive. ... Hence, from this it is clear that sodium is less reactive than potassium.
Explanation:
Which of the following increases the ratio?
Both β+ and β– decay
Only β– decay
Neither β+ nor β– decay
Only β+ decay
Answer:
Only β+ decay
Explanation:
In positron emission, a proton is converted into a neutron and a positron. An anti neutrino is a particle that serves the purpose of balancing the spins.
During positron emission, the mass number to the daughter nucleus is the same as that of the parent nucleus but the atomic number of the daughter nucleus is less than that of the parent nucleus by one unit.
Positron emission increases the neutron/proton ratio.
Equal mases of ethane and hydrogen are mixed in an empty container at 25 degree celcius.The fraction of the total pressure exerted by hydrogen is
Answer:
15/16
Explanation:
We need to find the number of moles of hydrogen and number of moles of ethane present.
Since we have the same mass, m for both substances, the number of moles of hydrogen, n = m/M where M = molar mass of hydrogen molecule
Since hydrogen is H₂, M = 2 × 1 g/mol = 2 × 1 g/mol = 2 mol.
n = m/M
n = m/2
Also, number of moles of ethane, n' = m/M' where M' = molar mass of ethane.
Since ethane is C₂H₆, M' = 2 × 12 g/mol + 6 × 1 g/mol = 24 g/mol + 6 g/mol = 30 g/mol
n' = m/M'
n' = m/30
The total number of moles of gas present is thus n" = n + n' = m/2 + m/30 = (15m + m)/30 = 16m/30
The mole fraction of hydrogen is thus number of moles of hydrogen/total number of moles = n/n" = m/2 ÷ 16m/30 = m/2 × 30/16m = 15/16
Also, since the partial pressure due to hydrogen, P = mole fraction × total pressure, P'
P/P' = mole fraction = 15/16
So, The fraction of the total pressure exerted by hydrogen is 15/16
According to the kinetic-molecular theory, the average kinetic energy of gas particles depends on which factor?
Answer:
Temperature.
Explanation:
Kinetic molecular theory of gases states that gas particles exhibit a perfectly elastic collision and are constantly in motion.
According to the kinetic-molecular theory, the average kinetic energy of gas particles depends on temperature.
This ultimately implies that, the average kinetic energy of gas particles is directly proportional to the absolute temperature of an ideal gas. Thus, an increase in the average kinetic energy of gas particles would cause an increase in the absolute temperature of an ideal gas.
Temperature can be defined as a measure of the degree of coldness or hotness of a physical object. It is measured with a thermometer and its units are Celsius (°C), Kelvin (K) and Fahrenheit (°F).
Hi Everyone ✌
hope u all r doin well
Pls Answer
What happens when dilute sulphuric acid is poured on a copper plate ?
Answer:
No observable change.
Explanation:
Copper renders dilute sulphuric acid passive, no reaction.
H2SO4+Cu-->CuSO4+H2
Explanation:
THIS IS THE CORRECT ANSWER
Antara berikut ciri manakah bear tentang cuka?
A. Berasa pahit.
B. Berasa tawar.
C. Nilai pH kurang dari 7
D. Nilai pH ialah 7
Answer:
c. nilai pH kurang dari 7
Explanation:
cuka adalah acid
nilai pH bagi acid adalah
antara 1 hingga 6
The osmotic pressure of a solution formed by dissolving 0.231 g of the protein in 150 mL of water at 298 K is found to be 2.054 torr.
Answer:
13924g/mol is the molar mass of the protein
Explanation:
What is the molar mass of the protein.
The osmotic pressure of a solution, π, is defined as:
π = c*R*T
Where π is osmotic pressure = 2.054torr* (1atm/760torr) = 2.70x10⁻³atm
c is molar concentration of the protein,
R is gas constant = 0.082atmL/molK
And T is absolute temperature = 298K
Solving the molar concentration:
c = π / RT
c = 2.70x10⁻³atm / 0.082atmL/molK*298K
c = 1.106x10⁻⁴ moles protein / L
The moles of protein in 150mL = 0.150L:
0150L * (1.106x10⁻⁴ moles protein / L) = 1.659x10⁻⁵ moles protein
The molar mass is the ratio of mass and moles:
0.231g / 1.659x10⁻⁵ moles protein =
13924g/mol is the molar mass of the proteinwhich is an example of the force of attraction between two obects that have mass?
Answer:
gravity
Explanation:
Gravity is an example of the force of attraction between two objects that have mass.
name any two mix metals with one use from each.
Answer:
bronze, copper
Explanation:
bronze is used to make medals and carve statues
copper is used to make wire and utensils
Which reaction occurs at the cathode of a galvanic cell that has an aluminum electrode in an electrolyte with aluminum ions and copper electrode in an electrolyte with copper ions ? The reduction potential for the reduction of Cu^ 2+ = 0.34 The reduction potential for the reduction of AP^ 3+ =-1.68V.
Answer:
[tex]{ \bf{Cu {}^{2 + } + 2e \: → \: Cu }}[/tex]
The reaction that occurs at the cathode of a given galvanic cell is:
Cu²⁺ + 2e⁻ → Cu
What is Galvanic Cell?A galvanic cell can be defined as an electrochemical cell that converts the chemical energy of spontaneous redox reactions into electrical energy. The galvanic cell makes use of chemical reactions to generate electrical energy.
A galvanic cell consists of two half-cells and a salt bridge. Each half-cell further contains an electrode dipped into an electrolyte. When both electrodes are dipped in the same electrolyte, then there is no need for a salt bridge.
At the anode, an oxidation reaction occurs at this electrode. At the cathode, reduction occurs at this electrode. The anode has a negative potential with respect to the solution while the cathode has a positive potential with respect to the solution.
As in the question, the reduction of Cu²⁺ has a positive reduction potential. Therefore, the reduction of the copper will occur at the cathode.
Learn more about Galvanic cell, here:
https://brainly.com/question/13031093
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Select the atoms that are likely to gain electrons to form anions:
A. Cesium (Cs)
B. Chlorine (CI)
c. Nitrogen (N)
D. Sulfur (S)
hurryyy asap make u the brainlyeist
Answer:
c
Explanation:
0.18 g of a divalent metal was completely dissolved in 250 cc of acidsolution containing 4.9 g H2SO4 per liter. 50 cc of theresidual acid solution required 20 cc of N/10 alkali forcomplete neutralization. Calculate the atomic weight of metal.
goodnight Gucci chunk cubic DDF if f Ch BK
Roundup, a herbicide manufactured by Monsanto, has the formula C3H8NO5P. How many moles of molecules are there in a 647.3-g sample of Roundup?
I got the answer 2.305 x 10^24 but for some reason it’s not working. Is it the wrong one?
Answer:
3.830177515 moles
Explanation:
You have :
647.3 g of RoundupMolar mass of Round up which is equal to 169 g.moland the formula: n=m/MTherefore: n=647.3/169
=3.830177515 moles
You're a dentist and want your patients to have the cleanest smiles possible. You're not sure which toothpaste to recommend and decide to design an
experiment to determine which toothpaste gives the brightest and whitest smile.
1) What variables would you need to control in your
experiment?
2) Which variable would you change to determine which toothpaste is best?
3) What is the measurable outcome for this experiment?
d) What would the procedure be for your experiment? Please help me to answer this questions:(
Answer:
Why do you need good toothpaste?
Explanation:
Answer:
Do this yourself smh this isnt what the wesite is for
Explanation:
Match each word to its correct meaning. 1. carbon sequestration carbon dioxide, water vapor, methane, nitrogen oxides, and some CFCs that absorb heat and keep it in the earth's atmosphere 2. greenhouse effect technology used to capture the carbon released from smokestacks and store it in some part of the environment to keep it out of the atmosphere 3. greenhouse gas a term used to describe the role that greenhouse gases play in keeping the earth warm
Answer:
1. Greenhouse gas.
2. Carbon sequestration.
3. Greenhouse effect.
Explanation:
Greenhouse gases can be defined as gases that trap heat within the Earth's atmosphere. Thus, an increase in global temperature is largely caused due to an increase in the amount of greenhouse gases in Earth's atmosphere.
Some examples of greenhouse gases present in the atmosphere are methane, water vapor, carbon dioxide etc.
Matching the descriptions with their term respectively, we have;
1. Greenhouse gas: carbon dioxide, water vapor, methane, nitrogen oxides, and some CFCs that absorb heat and keep it in the earth's atmosphere
2. Carbon sequestration: it's a technology used to capture the carbon released from smokestacks and store it in some part of the environment to keep it out of the atmosphere. Thus, it's a process that is typically used for capturing and the long-term storage of atmospheric carbon dioxide in soil, ocean, plants and geologic formation, so as to reduce global warming or climate change.
3. Greenhouse effect: it's a term used to describe the negative role that greenhouse gases such as methane, water vapor, carbon dioxide etc., play in keeping the earth warm.
