Answer:
1.63 × 10²⁴ atoms.
Explanation:
To calculate the number of atoms (N) contained in 2.7moles of carbon, we multiply the number of moles (n) by Avogadro's number (6.02 × 10²³).
That is, N = n × nA
Where;
N = number of atoms
n = number of moles (mol)
nA = Avogadro's numbe
N = 2.7 × 6.02 × 10²³
N = 16.254 × 10²³
N = 1.63 × 10²⁴ atoms.
Hence, there are 1.63 × 10²⁴ atoms in 2.7moles of Carbon.
Define the boiling and evaporation using kinetic theory
Answer:
Explanation:
By the kinetic molecular theory (particle model), all matter consists of particles, there are spaces between the particles, the particles are in constant random motion, and there are forces of attraction and repulsion between the particles.
Furthermore, temperature is defined to be a measure of the average kinetic energy of the particles.
Evaporation is a change of phase from liquid to gas explained as follows :
When particles in the liquid phase are heated, they gain kinetic energy and move faster and further apart. Eventually they have enough energy to escape the forces of attraction holding them together in the liquid phase and they move very fast and far from each other and exist in the gaseous phase.
Which of the following is true of science?
O It can be disproven by philosophy and religion.
O It does not change after new evidence is discovered.
O It is based on the personal opinions of scientists.
O It is based on testable and replicable evidence.
Answer:
I know the other person already said this but it would be the last option : )
A se ion has a mass number of 77
and a charge of −2
. Determine the number of neutrons, protons, and electrons in this ion.
Answer: The number of protons are 34, number of neutrons are 43 and number of electrons are 36 in the given Se ion
Explanation:
The atom consists of 3 subatomic particles:
Protons: They are positively charged particles present in the nucleus of an atom.Electrons: They are negatively charged particles present in the orbits around the nucleus of an atom.Neutrons: They are neutral particles present in the nucleus of an atom.The mass number is the sum of the number of protons and number of neutrons in the nucleus of an atom. These are known as nucleons
The atomic number is defined as the number of electrons or number of protons present in an atom.
We are given:
A Se ion having mass number 77
Atomic number of Se = 34
Number of protons = 34
Number of neutrons = 77 - 34 = 43
Number of electrons = Atomic number - Charge
Charge = -2
Number of electrons = [34 - (-2)] = [34 + 2] = 36
Hence, the number of protons are 34, number of neutrons are 43 and number of electrons are 36 in the given Se ion
What is the pOH of a 1 x 10^-8 M solution of HNO3?
Explanation:
to find POH u need PH first
so ph=-log(h3o)
so
[tex]ph = - log(1 \times {10}^{ - 8} ) \\ \\ ph = 8 \\ ph + poh =14 \\ poh = 14 - 8 \\ poh = 6[/tex]
List the two pairs of atoms referred to in the
previous question in order of increasing ionic
character of the bonding between them.
Help me with this question
Define a unit? write it's type
Answer:
Unit is the standard assigned to measure physical quantity. ... Length, mass, time, temperature, luminous intensity, and the electric current are known as the fundamental quantities. These are represented by L, M, T, 0, Cd, and A respectively
OAmalOHopeO
Which of the following compounds is usually
added to a swimming pool to prevent the growth
of algae ?
A. Caso
B. Cuso
C. PbSO
D. MgSO
4
4
4
4
set goals and objectives for a company
Explanation:
Objectives and goals serve as a foundation for successful organizations since they establish the business's objective and aid in the identification of required measures. Goals are broad assertions of what you want to achieve, whereas goals are the precise stages or steps you need to take to get there.
Question 24 Multiple Choice Worth 2 points)
[BWS.02] Why is science important for society?
Answer:
Because the scientific knowledge itself helps solve many basic human needs and it also improves how humans live and their standards. For example, without science medications wouldn´t exist and many technological devices we use now-a-days. We´re surrounded by science, we just don´t really notice it.
URGENT!!!
Which of the following describes a property of water that helps sustain marine life forms? (5 points)
a. Open spaces in water's solid structure makes its solid state less dense than its liquid state.
b. Water contracts on cooling below 4 °C, lowering its density until it reaches 0 °C.
c. Water freezes from bottom to top, which allows it to form a solid layer of ice only at the bottom of rivers and lakes.
d. Water has a very low specific heat capacity, allowing it to heat up quickly.
Answer:
a.) open spaces in waters solid structure makes its solid state less dense than its liquid state.
Answer: It is a.) open spaces in waters solid structure makes its solid state less dense than its liquid state.
Explanation: This is because the solid state of water is less dense than its liquid state due to free spaces in its solid structure.
How much heat must be transferred to 1600 g of iron to change the iron's
temperature from 202°C to 214°C? (The specific heat capacity of iron is
0.450 J/g.°c.)
O A. 8600 J
O B. 3.4 J
O C. 300
O D. 60 J
Answer:
A. 8600 J
General Formulas and Concepts:
Thermochemistry
Specific Heat Formula: q = mcΔT
q is heat (in J)m is mass (in g)c is specific heat (in J/g °C)ΔT is change in temperature (in °C)Explanation:
Step 1: Define
[Given] m = 1600 g
[Given] ΔT = 214 °C - 202 °C = 12 °C
[Given] c = 0.450 J/g °C
[Solve] q
Step 2: Find Heat
Substitute in variables [Specific Heat Formula]: q = (1600 g)(0.450 J/g °C)(12 °C)Multiply [Cancel out units]: q = (720 J/°C)(12 °C)Multiply [Cancel out units]: q = 8640 JStep 3: Check
Follow sig fig rules and round. We are given 2 sig figs as our lowest.
8640 J ≈ 8600 J
Topic: AP Chemistry
Unit: Thermodynamics
When a catalyst is added to a chemical reaction it provides a new reaction pathway that results in a different
Answer: That results in a different ALTERNATE pathway which has a LOWER ACTIVATION ENERGY.
Explanation:
There are many factors that affects a chemical reaction, these include'
--> surface area
--> concentration,
--> temperature,
--> pressure and
--> presence of CATALYST.
A CATALYST is defined as the substance that has the ability to alter the rate of a chemical reaction. Many reaction very slowly when left alone, but become faster when other substances are added. Such substances that merely alter the rate of reactions but do not take part in the reactions are called CATALYSTS.
Activation energy is defined as the energy barrier that must be overcome before a reaction takes place. A catalyst is able to increase the rate of a chemical reaction by decreasing the activation energy of the chemical system.
A catalyst provides an ALTERNATE PATHWAY for the reaction that has a LOWER ACTIVATION ENERGY. When activation energy is lower, more reactant particles have enough energy to react, so the reaction occurs faster.
what type of chemical is manganese(IV) oxide
Answer:
catalyst
Explanation:
it alters the speed of reaction
Is the following nuclear equation balanced?
No
Yes
Answer:
Yes.
The nuclear equation {226/88 Ra → 222/26 Rn + 4/2 He} is balanced. As we know that an alpha particle is identical to a helium atom. This implies that if an alpha particle is eliminated from an atom's nucleus, an atomic number of 2 and a mass number of 4 is lost.
Therefore, the equation will be reduced to:
226 - 4 = 222
88 - 2 = 86
Hence, the equation is balanced.
Explanation:
Answer:
yes
Explanation:
s]imple yes
Bacteria, viruses, parasites, and mold are examples of which category of hazard-causing agents?
Answer:
abiotic infectious agent
Explanation:
not sure tho
how many different sublevels are in the second energy level?
2
1
4
3
Answer:
The answer is 2
Explanation:
There are two energy sublevels in the second principal energy level. These two energy sublevels are 2s and 2p. The energy distribution in an atom is divided into a number of principal energy levels, and the principal energy levels are again divided into four basic energy sublevels.
Heavy rains fill a reservoir, causing the dam that holds the water to break. As a result, the areas downstream are suddenly flooded. Which question would a scientist seek to answer?
Answer:
"How to prevent the collapse of the dam that contains water from heavy rains?"
Explanation:
Scientists must work to create innovations capable of bringing benefits to human life and combating disadvantageous and harmful situations. The overflow of dams is something very harmful, as the resulting flooding can cause structural, economic and even public health problems. When this overflow is caused by natural elements, such as heavy rains, the work of scientists in solving these issues is even more important and necessary. In order to resolve the dam failure caused by excess rainwater, scientists must work to answer the following question:
"How to prevent the collapse of the dam that contains water from heavy rains?"
Applicable in case of strong acid–
(i) gets completely ionized in aqueous solutions
(ii) gives H+ ion in aqueous solution
(iii) sour in taste
Which one is correct?
A
i, ii, iii
B
i, ii
C
ii, iii
D
i, iii
Answer:
A. i, ii, iii
Explanation:
A strong acid gets completely ionized in aqueous solutions releasing a large number of hydrogen ions. It also has a sour taste.
A student is investigating the effect of concentration on the colour of a solution of copper sulfate.She wished to make up 250cm^3 of a solution if copper sulfate with a concentration of 0.5 mol/dm^3 that she can dilute. a solution with the concentration of 0.50 mol/dm^3 contains 0.50 mol of copper sulfate per decimetre cubed calculate the concentration of this solutionin g/dm^3
Answer:
79.8g/dm³
Explanation:
As you can see, the solution in the problem contains 0.5 moles of copper sulfate per dm³. To solve this question we must convert these moles to grams using its molar mass (Molar mass CuSO4 = 159.609g/mol) as follows:
0.5mol CuSO4/dm³ * (159.609g/mol) =
79.8g/dm³ Hellppppp ASAP Will mark brainliest !!!!Which of the following metals is paramagnetic
A.Beryllium
B.Calcium
C.sodium
D.Magnesium
Answer:
A. Berryllium is a paramagnetic
Physical properties can be divided into two categories. _______ depend on the amount of matter present, while _______ don't.
Are your knees the elbows of your legs or are your elbows the knees of your
arms?
A.knees are elbows of your legs
B.elbows are knees of your arms
C.both
Answer:
Both :)
Explanation:
Knees and elbows are the types of joints that are present to move the parts of the body attached to it. The knees are the elbows, and the elbows are the knees.
What are joints?The joints knees and elbows work like the door and allow the movement of the attached body parts in back and forth directions.
The elbow of the arm region and the knee of the leg region have similar functions and are homologous in the function that moves the leg of the lower region and the arm of the upper region.
Therefore, option c. both is the correct option.
Learn more about knee and elbow here:
https://brainly.com/question/27056104
what mass of water will be formed when 3g of hydrogen react with 30g of oxygen?
Answer: Write down the chemical equation first;
2H2 + O2 —-> 2H2O
2. Since the mass is given, use it to calculate the mole for each reactant;
mole = mass / molar mass
mole of H2 : 8/2 = 4 mole
mole of O2 : 30/16(2) = 0.9375 mole
Now, if you're not sure which reactant to use to calculate the mass of H2O using ratio since both answer are different, find the limiting reactant.
From the equation;
2 mol of H2 -> 2 mol of H2O
4 mol of H2 -> (4*2)/2 = 4 mol of H20
______________________________________
1 mol of O2 -> 2 mol of H2O
0.9375 mol of O2 -> (0.9375*2)/1 = 1.875 mol of H2O
Let's take a look at both numbers. Since H2 produces more water than O2, O2 will be the limiting reactant as it has the least mole of H2O. So now we are going to use O2 as our limiting reactant. Use the formula to calculate mass of water using mole.
mass of H2O : 1.875*(16+2) = 33.75 g
Thats it. Correct me if im wrong
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
The Sulphate of x is XSO4 valency of x is
Answer: m mm
/lk ac
Explanation:
Which coefficients correctly balance the formula equation below?
AgNO3 + CuCl2 → AgCl + Cu(NO3)2
2, 1, 2,1
1, 1, 3,1
2, 2, 3,1
2, 1, 1,2
Answer:
2, 1, 2,1
Explanation:
The chemical equation of the reaction given in this question is as follows:
AgNO3 + CuCl2 → AgCl + Cu(NO3)2
The reaction is between silver nitrate (AgNO3) and copper (I) chloride (CuCl2) to form silver chloride (AgCl) and copper nitrate (Cu(NO3)2.
However, this above equation is not BALANCED because the number of atoms of each element on both sides of the equation does not equate i.e. are not the same. To balance the equation, we have to make use of COEFFICIENTS, which are numbers used in front of each element in order to balance the equation.
The balanced equation is as follows:
2AgNO3 + CuCl2 → 2AgCl + Cu(NO3)2
From the above balanced equation, we can observe that coefficients used to balance the equation is in the order: 2, 1, 2,1
PLEASE HELP ME!
-The compound dissolves in water to form a solution with pH > 7.
- The compound has a low boiling point.
The elements P, Q, R and S have proton number of 1, 7, 11 and 17.
Which of the following pair of elements will react to form a compound with the characteristics stated in the table above?
A. P and Q
B. R and S
C. Q and R
D. P and S
Answer:
C
Explanation:
Q and R forms a nitrate. When dissolved in water it will form a solution with a pH greater than 7 because the solution is alkaline.
PLEASE HELP ME!
Aspartame is an artificial sweetener that is 160 times sweeter than table sugar. It is marketed as Pal-Sweet. The molecular formula of aspartame is C¹⁴H18N²O5.
i) Name the elements that made up aspartame. [2 marks]
(ii) Calculate the relative molecular mass of aspartame. [2 marks]
(iii) Calculate the number of moles in 7.35g aspartame. [3 marks]
(iv) Calculate the number of molecules in 5.88 g aspartame. [2 marks]
(v) Calculate the mass in grams of one molecule of aspartame. (H=1, C=12, N=14, 0=16, N = 6 x 10²³mole) [3 marks]
Answer:
A. Carbon, Hydrogen, Nitrogen, and Oxygen
B. 12(14) + 1(18) +12(2)+16(5)= 294.20g
C. 7.35/294.3=0.0250mol
D. 5.88g/294.3=0.01997961264 × 6.02 × 10^2= 12.028
Explanation:
Calculate the percent water in ZnSO4.7 H20. Show your work.
Answer:
43.8%
Explanation:
Find the sum of the relative atomic mass of all the elements constituting the compound, which is known as the relative formula mass;
[tex]M_{r} = Relative \ formula \ mass \\\\M_{r} \ of \ ZnSO_{4} = 65.4 + 32.1 + 4(16) \\\\M_{r} \ of \ ZnSO_{4} = 97.5 + 64 \\\\M_{r} \ of \ ZnSO_{4} = 161.5 \\\\M_{r} \ of \ H_{2}O = 18 \\\\M_{r} \ of \ ZnSO_{4}.7H_{2}O = 161.5 + 7(18) \\\\M_{r} \ of \ ZnSO_{4}.7H_{2}O = 287.5[/tex]
Then, divide the relative formula mass of all the water by that of the whole compound
w = % water
[tex]w = \frac{7(18)}{287.5} * 100 \\\\w = 0.43826... * 100\\\\w = 43.826...[/tex]
w = 43.8%
Name the following aromatic hydrocarbon:
Explanation:
I think option 3..............