Answer:
Nobles Gases Are the group of elements which are generally unreactive
I Hope its right if not then Sorry, have a wonderful day :)How can the percentage of air be determined
Answer:
The composition of air can be determined by an experiment which includes passing a known volume of air, measured at a known temperature and pressure, over sufficient amount heated copper granules/powder, and measuring the volume gas remaining after the gas cools down to the temperature at which the first measurement was taken
Oxygen reacts with copper according to the following chemical reaction
2Cu (s) + O₂ (g) → 2CuO (s)
Cupper does not react with the other constituents of air
Whereby the initial volume of air was 100 cm³, we have;
Percentage of oxygen in air = 100 - The final volume reading of the container initially holding the air
When done using am appropriate experimental setup, the percentage of gases remaining equals 79% to 80%, therefore, the percentage composition of oxygen in air is between 20 and 21 percent
Explanation:
Name one diatomic compound which is mononuclei
Answer:
Common diatomic molecules include hydrogen (H2), nitrogen (N2), oxygen (O2), and carbon monoxide (CO). Seven elements exist as homonuclear diatomic molecules at room temperature: H2, N2, O2, F2, Cl2, Br2, and I2. The bond in a homonuclear diatomic molecule is non-polar due to the electronegativity difference of zero.
Which equation describes a physical change? i. H2O(s) ⟶ H2O(l) ii. Na+(aq)+Cl−(aq) +Ag+(aq)+NO3−(aq) ⟶ AgCl(s)+Na+(aq)+NO3−(aq) iii. CH3OH(g)+O2(g) ⟶ CO2(g)+H2O(g) iv. 2H2O(l) ⟶ 2H2(g)+O2(g) v. H+(aq)+OH−(aq)⟶ H2O(l)
Answer:
The answer is "Option i"
Explanation:
In this question, only option (i) is correct, and others were wrong which can be defined as follows:
In option (ii):
[tex]Na^+\ (aq)+Cl^- \ (aq) +Ag^+ \ (aq)+NO_3^- \ (aq) \to AgCl\ (s)+Na^+ \ (aq)+NO_3^-\ (aq) \\\\[/tex]
It is the complete ionic equation.
In option (iii):
[tex]CH_3OH\ (g)+O_2\ (g) \to CO_2\ (g)+H_2O\ (g)[/tex]
It is the combustion reaction but a not balanced equation.
In option (iv):
[tex]2H_2O\ (l) \to 2H_2\ (g)+O_2\ (g)[/tex]
It is the decomposition equation.
In option (v):
[tex]H^+\ (aq) +OH^-\ (aq)\to H_2O\ (l)[/tex]
It is the complete ionic equation.
How many liters are in 4.5 moles of CO2 gas at STP? Pls help :)
Answer:
Explanation:
NCO 2= 4,5
VCO2= 4,5* 22,4=100,8
What are 5 uses of nitrogen?
Answer:
nitrogen is used in the production of 1) fertilisers 2) nitric acid 3) nylon 4) dyes and 5) explosives
please give me brainliest if you can :))
Do different color lights (RBG) use additive or subtractive properties to bring light of a certain color to our eyes?
Answer:
The lighting filters use subtractive properties to bring light of a color to the eye because subtractive color mixing uses white light source with a series of filter to eliminate certain wavelengths of light.
Different colour lights (RBG) uses additive properties to bring light of a certain color to our eyes.
What is color synthesis?Color synthesis is the art of forming different types of colours from small number of primary colours. The color formed is called a secondary color.
Color synthesis is carried out through the following means:
Additive color synthesis andSubtractive color synthesis.In additive color synthesis, the three primary colours lights that are combined is Red(R), Blue (B) and Green(G).
The wavelength from the various color light combine to generate white light which is visible to the eye.
Therefore, different colour lights (Red, Blue and Green) uses additive properties to bring light of a certain color(white) to our eyes.
Learn more about color synthesis here:
https://brainly.com/question/18452279
help me pls! plsssss
Answer:
Neutron, neutral subatomic particle that is a constituent of every atomic nucleus except ordinary hydrogen. It has no electric charge and a rest mass equal to 1.67493 × 10−27 kg—marginally greater than that of the proton but nearly 1,839 times greater than that of the electron.
What is the standard reduction potential, E, for the half-reaction Al3+ (aq)
3e- -> Al(s)?
Answer:
E° = -1.66 V
Explanation:
The standard reduction potential is also known as the standard electrode potentials and it tries to find the probability that an element will be reduced or undergo reduction.
From activation series online showing the standard reduction potentials for half cells, the standard reduction potential of Al3+ (aq) + 3e- -> Al(s) is;
E° = -1.66 V
Explain how the existence of ions relates to the number of electrons present in atoms of an element? (A.P.E.X)
Answer:
if you have options please include them, but I'll give you an idea.
Explanation:
The existence of ions happens when atoms lose or gain electrons.
if an atom gains an electron it will become a negative ion (because electrons are negative, and you gained more negativity.)
if an atom loses an electron it will become a positive ion (because it has lost negativity, which is the electron that we've lost).
I hope it helps, if it does please mark me brainliest!
A piece of unknown metal with mass 68.6 g is heated to an initial temperature of 100 °C and dropped into 8.4 g of water (with an initial temperature of 20 °C) in a calorimeter. The final temperature of the system is 52.1°C. The specific heat of water is 4.184 J/g*⁰C. What is the specific heat of the metal?
0.171
0.343
1.717
3.433
Answer:
1.717
Explanation:
Bài 19 với ạ, ai giúp em với ❤️❤️❤️❤️❤️
Answer:
we're are u from
Explanation:
also the writing from that paper look really cool
A piece of sodium metal can be described as?
Select the correct answer.
Which statement accurately describes natural selection?
A.
It ensures that 100 percent of beneficial traits will pass on to the next generation.
B.
It ensures that all individuals with harmful traits are unable to reproduce.
C.
Individuals with beneficial traits are more likely to successfully reproduce than those with harmful traits.
D.
Individuals are all equally likely to successfully reproduce, but the genome will mutate to erase harmful traits.
Answer:
D .
Explanation:
Individuals are all equally likely to successfully reproduce, but the genome will mutate to erase harmful traits.
Nal+ pb(SO4) 2 Pbl4 + Na2SO4 explain how to balance the chemical equation and classify its reaction type
Explanation:
because there are 4 Iodines on the left, we'll put. 4 in front of NaI to balance it. This would result in 4 Na on the left, so we'll put a 2 in front of Sodium Sulfate to balance the right side. Now we have 4 Na and I on both side, as well as 2 Sulfate on both sides. Pb is already balanced. The equation is now complete.
What is the quantity of carbon-14 in a bone after 17,190 years if the initial mass of C-14 is 0.300 grams and the half-life is 5,730 years?
A.
0.038 g
B.
0.093 g
C.
0.281 g
D.
0.412 g
A. 0.038 g.
Explanation:
The decay of carbon-14 is a first order reaction.
The rate constant of the reaction (k) in a first order reaction = ln (2)/half-life = 0.693/(5730 year) = 1.21 x 10⁻⁴ year⁻¹.
The integration law of a first order reaction is:
kt = ln [Ao]/[A]
k is the rate constant = 1.21 x 10⁻⁴ year⁻¹.
t is the time = 17,190 years.
[Ao] is the initial concentration of carbon-14 = 0.300 g.
[A] is the remaining concentration of carbon-14 = ??? g.
∵ kt = ln [Ao]/[A]
∴ (1.21 x 10⁻⁴ year⁻¹)(17,190 years) = ln (0.300 g)/[A]
2.08 = ln (0.300 g)/[A]
Taking exponential for both sides:
8.0 = (0.300 g)/[A]
∴ [A] = 0.0375 g ≅ 0.038 g
PLZ HELP ME WITH MY WORK
Answer:
Explanation:
pretty sure its mixure.
At what approximate temperature and pressure can all three phases of water exist simultaneously?
0°C, 760 mmHg
0°C, 5 mmHg
80°C, 380 mmHg
100°C, 760 mmHg
Answer:
0⁰c , 5 mmHg
Explanation:
Because at this temperature we all know water can be in state of both solid and liquid and when pressure is decreased it can be in form of gas too
PLEASE URGENT HELP!! 30 POINTS!!!!!!
Answer:
CH³–C=CH——CH³–CH=CH²
Explanation:
THIS IS PROPYNE TO PROPENE
balanced chemical equation:Copper( ii) oxide solid +dilute sulphuric acid
Answer:
CuO + H2SO4 = CuSO4 + H2O
Reaction type: double replacement
what is electronic configuration?
Answer:
In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule in atomic or molecular orbitals.
57:17
A ball that has a mechanical energy of 65 J has 12 J of kinetic energy. The ball has blank
energy.
J of potential energy
Answer:
53 Joules
Explanation:
Applying the law of conservation of mechanical energy.
Law of conservation of mechanical energy: States that energy although, energy can not be transformed from one form to another, the total energy of the system remain the same.
I.e,
Mechanical Energy = E.K+P.E..................... Equation 1
Where E.K = Kinetic energy, P.E = Potential energy.
From the question,
Given: Mechanical energy = 65 Joules, K.E = 12 J
Substitute these values into equation 1 and solve for P.E
65 = 12+P.E
P.E = 65-12
P.E = 53 Joules
HF or HCl which can form the hydrogen bond? Explain your answer.
Answer:
can only form one hydrogen bond each
Explanation:
can only form one hydrogen bond each
When under a pressure of 9.5 atm, a piston has a volume of 1.7 liters. It the piston is compressed to a
volume of 1.1 liters, what will the new pressure be?
c. 8.90 atm
a. 5.08 atm
b. 6.15 atm
d. 14.7 atm
Answer:
D
Explanation:
according to boyle's law the temperature and pressure of a gas are inversely proportional given by the equation
p1v1=p2v2
In this case p1 is 9.5,v1 is 1.7,v2 is 1.1 and we have to find p2
9.5×1.7=p2×1.1
16.15/11=1.1p2/1.2
p2=14.7
I hope this helps
Answer:
[tex]\boxed {\boxed {\sf D.\ 14.7 \ atm}}[/tex]
Explanation:
We are asked to find the pressure on a gas given a change in volume. We will use Boyle's Law which states the volume of a gas is inversely proportional to the pressure. The formula for this law is:
[tex]P_1V_1=P_2V_2[/tex]
The gas originally has a pressure of 9.5 atmospheres and a volume of 1.7 liters.
[tex]9.5 \ atm * 1.7 \ L = P_2V_2[/tex]
The gas is compressed to a volume of 1.1 liters, but the pressure is unknown.
[tex]9.5 \ atm * 1.7 \ L = P_2* 1.1 \ L[/tex]
We want to find the new pressure, so we must isolate the variable P₂. It is being multiplied by 1.1 liters. The inverse operation of multiplication is division. Divide both sides of the equation by 1.1 L.
[tex]\frac {9.5 \ atm * 1.7 \ L}{1.1 \ L} =\frac{ P_2* 1.1 \ L}{1.1 \ L}[/tex]
[tex]\frac {9.5 \ atm * 1.7 \ L}{1.1 \ L} =P_2[/tex]
The units of liters cancel.
[tex]\frac {9.5 \ atm * 1.7 }{1.1 } =P_2[/tex]
[tex]\frac {16.15}{1.1} \ atm =P_2[/tex]
[tex]14.6818181818 \ atm= P_2[/tex]
Round to the tenths place. The 8 in the hundredth place tells us to round the 6 up to a 7.
[tex]14.7 \ atm \approx P_2[/tex]
The new pressure at a volume of 1.1 liters is approximately 14.7 atmospheres.
hii pls help me to balance the equation and state the symbols thanksss
Answer:
I DID HOW I KNOW . I HOPE IT WILL HELP YOU :D
The seeds of a dandelion are wispy and very light. A single dandelion produces many seeds. How does the structure of the seeds relate to the dandelion's method of spreading seeds?
A Dandelion seeds are spread mainly by the wind. Because they are light, the wind can carry them. The dandelion produces many seeds because not all seeds will land in a good location to sprout.
B. Dandelion seeds are spread primarily by becoming attached to animals' fur. Because they are light, the animals can cany many without noticing. The dandelion produces many seeds because not all seeds will land in a good location to sprout
C. Dandelion seeds are spread mainly by animals that eat them Because they are light the animals will eat many seeds. The dandelion produces many seeds in order to outcompete other plants for resources
D. Dandelion seeds are spread primarily by moving water. Because they are light, they will float on the water. The dandelion produces many seeds in order to outcompete other plants for resources. SIMIT
Answer:
the answer will be number...D
Answer:
The answer is A
Explanation:
Because dandelions are wispy and very light, the slightest gasp of wind helps carry the dandelions to new locations and help reproduce the seed into a new dandelion.
1. In regards to curly hair, which of the following statements
are TRUE? (select 2 answer choices).
A. Curly hair develops over time. It is not acquired at birth.
B. Curly hair can lead to harmful mutations in the body.
C. Curly hair results from a change in the gene that
codes for hair structure.
D. People with curly hair have different hair protein structures than people with
straight hair.
Answer here:
Answer:
A and D are the answers
Explanation:
the other two don't make sense
The statements C and D are correct, i.e., curly hair have different protein structure from straight hair and curly hair results from a change in the gene.
What is protein?Proteins are biomolecules made of amino acids. Proteins are very essential to all living things and contributes the body structure. Proteins are mainly up taken through diet and they are the main source of energy.
Hair is made of keratin protein. Keratin makes up our skin and nails too.Curly hair is originating by birth not developing over time. Curly hair is more likely to be occurring through inheritance.
The protein structure the hair follicle is some more bend for curly hair. Curly hair and straight hair originates from different gene traits. The gene type is inherited from the parents.
Hence, for people with curly hair have different protein structure and it result from a change in gene that code for hair structure. Thus options C and D are correct.
To learn more about proteins, refer the link below:
https://brainly.com/question/2193769
#SPJ2
Which factors ALL increase reaction rate?
decrease temperature, stir, increase surface area, remove catalyst
none of these
increase temperature, increase surface area, add catalyst, stir
increase temperature, stir, decrease surface area, add catalyst
Answer:
increase temperature, increase surface areas, add catalyst, stir
The rate of reaction can be increased with the increase in temperature, surface area, adding catalyst and allowing stirring. Thus, option C is correct.
What is rate of reaction?The rate of reaction is given as the rate of formation of product or the rate of disappearance of reactant in unit time.
The rate of reaction can be affected with:
Increase in temperature - It will increase the collisions between the reactants, and thereby the rate.Increase in surface area - It results in increased interaction of the reactant molecules for the formation of product.Catalyst - It lowers the activation energy of the reactant, and thereby increases the rate of reaction.Stirring - It mediates the increase in the collisions and the surface area, and resulting in increased rate of reaction.Thus, the rate of reaction can be increased with the increase in temperature, surface area, adding catalyst and allowing stirring. Thus, option C is correct.
Learn more about rate of reaction, here:
https://brainly.com/question/13440548
#SPJ2
PLZ HELP ME WITH MY WORK
How many different elements are there in the molecule C8H11NO2,?
A. 21
B. 2
c. 11
D. 4
Answer:
option C 11
is the correct answer
30 POINTS!! Will mark brainliest if correct answer and all work is shown! What mass in grams of tin would be required to completely react with 1.30 L of 0.750 M HBr in the following chemical reaction? Sn(s) + 4 HBr(aq) → SnBr₄ (aq) + 2 H₂ (g)
Answer:
mSn=0.24375*59=14.38125
Explanation:
nHBr=1.3*0.75=0.975
nSn=1/4nHBR=0.975/4=0.24375
mSn=0.24375*59=14.38125
A 45g Aluminum spoon (specific heat 0.88J/g degree Celcius) at 24 degrees Celcius placed in 180ml(180g) of coffee at 85 degrees Celcius and the temperature of the two become equal. What is the final temperature?
Answer:
82 °C
Explanation:
Let the specific heat capacity of the coffee be that of water which is 4.2 J/g °C.
Now, at the final temperature, heat gained by Aluminum spoon ,Q equals heat lost by coffee, Q'.
Q = -Q'
Q = m₁c₁(T₂ - T₁) where m₁ = mass of aluminum spoon = 45 g, c₁ = specific heat of aluminum = 0.88 J/g °C, T₁ = initial temperature of aluminum spoon = 24 °C and T₂ = final temperature of aluminum spoon.
Q' = m₂c₂(T₂ - T₃) where m₂ = mass of coffee = 180 g, c₂ = specific heat of coffee = 4.2 J/g °C, T₃ = initial temperature of coffee = 85 °C and T₂ = final temperature of coffee.
So, Q = -Q'
m₁c₁(T₂ - T₁) = -m₂c₂(T₂ - T₃)
Making T₂ subject of the formula, we have
m₁c₁T₂ - m₁c₁T₁ = -m₂c₂T₂ + m₂c₂T₃
m₁c₁T₂ + m₂c₂T₂ = m₂c₂T₃ + m₁c₁T₁
(m₁c₁ + m₂c₂)T₂ = m₂c₂T₃ + m₁c₁T₁
T₂ = (m₂c₂T₃ + m₁c₁T₁)/(m₁c₁ + m₂c₂)
substituting the values of the variables into the equation, we have
T₂ = (180 g × 4.2 J/g °C × 85 °C + 45 g × 0.88 J/g °C × 24 °C )/(45 g × 0.88 J/g °C + 180 g × 4.2 J/g °C)
T₂ = (64260 J + 950.4 J)/(39.6 J/°C + 756 J/°C)
T₂ = 65210.4 J/795.6 J/°C
T₂ = 81.96 °C
T₂ ≅ 82 °C
