Answer:
a) 0.000765kg
b) 1340mg
c) 0.0342g
Explanation:
a) 1000g = 1kg
0.765g= 0.765/ 1000
= 0.000765g
b) 1g = 1000mg
1.34g = 1.34 × 1000
= 1340mg
c) 1000mg = 1g
34.2mg = 34.2/1000
= 0.0342g
25 cm of liquid 'A' and 20 cm of liquid
'B' are mixed at 25°C and the volume of
solution was measured to be 44.8 cm3
then correct reaction is
(A) A Hmix = 0, solution shows
ideal
Answer:
The correct option is;
(B) [tex]\Delta H_{mix} < 0[/tex], solution shows negative deviation
Explanation:
The given parameters are;
The available volume of liquid A = 25 cm³
The available volume of liquid B = 20 cm³
The volume of the solution (mixture) = 44.8 cm³
Therefore, we have;
[tex]\Delta _{mix} V < 0[/tex]
Which is one of the prerequisite for the formation of negative deviation
When a non-ideal solution shows negative deviation according to Raoult's Law, we have;
[tex]\Delta _{mix} H < 0[/tex], we have more heat released due to new molecular interactions.
Why Hund's Rule is called maximum spin multiplicity rule?
Answer:
The rule states that for a given electron configuration, the lowest energy term is the one with the greatest value of spin multiplicity. This implies that if two or more orbitals of equal energy are available, electrons will occupy them singly before filling them in pair
Explanation:
1 pc
Calculate the volume of a an object that has a height of 14.3cm, length or
25.2cm, width of 6.7cm. *
46.2cm
2414.412 cm
0.085 cm
53.785 cm
Answer:0.085
Explanation:
list the elements symbols for the elements that are designated with neon green
Answer:
h,c,n,o,p those are the elements
A total of eighteen electrons can be placed into the 3rd energy level.
Explain WHY?
Answer:
each principal energy level above the second contains, in addition to one s orbital and three p orbitals, a set of five d orbitals, called the d sublevel. The five d orbitals can hold up to 10 electrons. Thus, the third level holds a maximum of 18 electrons: 2 in the s orbital, 6 in the three p orbitals, and 10 in the five d orbitals.
Explanation:
Which of the following best describes how Thomson
concluded that electrons are present in all atoms.
a
The charge-to-mass ratio of electrons is always the
same constant, no matter which substances are
used in the cathode ray tube.
b The cathode ray was able to turn a wheel.
The cathode ray always bent toward a negatively
charged plate.
d
The charge-to-mass ratio is unique to each different
element.
Answer: A
Explanation:
The charge-to-mass ratio of electrons is always the same constant, no matter which substances are used in the cathode ray tube.
Explanation:
Thomson in his model of atom discussed that the atom consists of a negative charge particle termed electron randomly distributed in the positively charged sphere to balance the negative charge.His model of the atom was also known as the Plum pudding model of the atom. In which electrons are embedded in positive soup.He discovered electrons by conducting an experiment with cathode rays in which cathode rays emerging from the cathode were observed to be deflected towards the positively charged plate.He also conducted the same experiment with different metals (for anode and cathode) and gases and found out that the charge to mass ratio of the electron was regardless of the metals or gases used in the experiment.With this, he landed on the conclusion that these particles of cathode rays are the universal component of matter.So, from this, we can conclude that the charge-to-mass ratio of electrons is always the same constant, no matter which substances are used in the cathode ray tube describes Thomson's conclusion that electrons are present in all atoms.
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A balloon is a sphere with a radius of 5.0 m. The force of air against the walls of the balloon is 45 N. What is the air pressure inside the balloon? Surface area = 12.56 × radius² 1 Pa = 1 N/m² How would I solve this problem? What are the steps or a good way to remeber how to solve?
Answer:
0.127 N/m² or 0.127 Pa
Explanation:
From the question given above, the following data were obtained:
Radius (r) = 5 m
Force (F) = 40 N
Pressure (P) =.?
Next, we shall determine the Surface area of the sphere (i.e the balloon). This can be obtained as follow:
Surface area = 12.56 × r²
Radius (r) = 5 m
Surface area = 12.56 × 5²
Surface area = 12.56 × 25
Surface area = 314 m²
Finally, we shall determine the pressure as follow:
Force (F) = 40 N
Surface area = 314 m²
Pressure (P) =.?
Pressure = Force /Area
Pressure = 40/314
Pressure = 0.127 N/m² = 0.127 Pa
Therefore, the pressure inside the balloon is 0.127 N/m² or 0.127 Pa.
What kinds of paintings did Winslow Homer make
Identify the property of the matter described below.
Alcohol floats on top of the water.
A-pH
B-conductivity
C-density
D-luster
Answer: C.
Explanation: Alcohol floats on oil and water sinks in oil. Water, alcohol, and oil layer well because of their densities, but also because the oil layer does not dissolve in either liquid. The oil keeps the water and alcohol separated so that they do not dissolve in one another. ... Water sinks because it is more dense than oil.
What is the mass of 4.39 mol Na?
Answer:
101 g Na
Explanation:
To convert between moles and grams, you have to use the molar mass of the substance. The molar mass of sodium is 22.99 g/mol. You use this as the unit converter.
[tex]4.39molNa*\frac{22.99gNa}{1molNa} = 100.9261gNa[/tex]
Round the number to the lowest number of significant figures; 101 g Na.
The mass of 4.39 moles of sodium (Na) is 100.97grams.
HOW TO CALCULATE MASS:The mass of a substance can be calculated by multiplying the number of moles in the substance by its molar mass. That is;Mass = no. of moles × molar mass
According to this question, there are 4.39 moles of Na. The molar mass of Na is 23g/mol.Mass of Na = 4.39 × 23
Mass of Na = 100.97grams.
Therefore, mass of 4.39 moles of sodium (Na) is 100.97grams.
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which of the following elements would decrease in size when it became an ion
Answer:
nickel, cobalt would decrease in size when it became an iron
If a wave of red light has a wavelength of 6.7 x 10-7 m, will the frequency of the red wave be high or low?
Answer:
Its high
Explanation:
Becuase if u times it what do u get
Which types of matter are made of atoms
a. Mixtures
b. Elements
C. Compounds
D. All of the above
Answer:
D all above yes I think it's all above
Answer: D
Explanation: All of the above.
Plz mark brainliest:)
How does the valence electron configuration (entire last energy level configuration) relate to the group number on the Periodic Table? Use the shorthand notation in your discussion.
Answer:
The valence electron configuration determines the group to which an element belongs to.
Explanation:
The valence electron configuration of an atom of an element refers to the number of electrons in that atoms outermost shell.
The valence electron configuration is related to the group number of an element in that the number of electrons in the valence shell of an atom of an element determines the group to which an element belongs to. For example, all elements having one valence electron belong to group IA of the periodic table. Similarly, all elements having seven valence electrons belong to group VIIA of the periodic table.
This is because, since the reactivity of an element is related to its ability to either gain or lose a certain number of electrons in its valence shell, elements having same number of valence electrons have similar chemical properties.
I need help with the 2nd part first gets brainlist
Answer:
7. 4H₂O
Elements: Hydrogen, Oxygen
Number of molecules: 4
Number of elements: 8 H, 4 O
Number of Atoms: 12
Explanation:
The elements are determined by the their symbol i.e. H = hydrogen.
The number of molecules is determined by the coefficient ( the number in front of everything, in this case 4).
The number of elements is determined by the coefficient and the subscripts. Multiply the coefficient by the subscript after each element. When there is no subscript, it is equal to 1. 4H₂ = 4x2 = 8; 4O = 4x1 = 4.
The number of atoms is all the individual elements added together. 8+4 = 12.
Which has a smaller ionic radius than it's neutral atom?
A. Iodine
B.Cesium
C.Oxygen
D.Nitrogen
Explanation:
Caesium (Cs) has a smaller ionic radius than it's neutral atom.
because Caesium belong to Group 1 and It loses 1 electron. After losing 1 electron it gains 1 positive charge that's why caesium ionic radius become smaller as compared to neutral atom.
Therefore,
Option B is correct.
What is a system?
A. An isolated piece of the world
OB. A liquid in which reactions take place
O C. A piece of scientific equipment
O D. A technique for recording data
Answer:
D. a technique of recording data
colonel flanders makes boxes of chicken with various numbers of pieces. He charges $ 0.40 for each piece of chicken, plus a fixed charge of $ 0.55 for the box, the rolls, etc. If Iddy Ottic bought the $6.95 box, how many piecesof chicken should the box contain?
stages of mitosis in order
Answer:
nucleus formed
prophase
metaphase
anaphase
telophase and cytokinesis
What is the atomic number of an atom?
O the number of neutrons
O the number of electrons and neutrons
O the number of protons
the number protons and neutrons
What explains the structure of metals and delocalized electrons?
A. the unit cell model
B. the geometric shape model
C. the covalent bond model
D. the electron sea model
Which of the following is the correct model of C7H16?
A.
B.
C.
D.
Answer:
D
Explanation:
Option D gives the correct model of C7H16. From the option, one will discover that the model has 7 carbons in the backbone. If you count the attached hydrogen, you will discover that the hydrogen is 16 in total.
This model or skeletal structure of this element represents heptane. Heptane or n-heptane is known to be a straight-chain compound and an alkane. It's chemical formula can also be written as: H₃C(CH₂)₅CH₃ or C₇H₁₆.
This compound is known to be one of the main components of gasoline. It is known to be a volatile organic compound and a clear and colorless liquids with a petroleum-like odor.
Answer: D
Explanation: Just took the test
Rubbing alcohol or isopropanol can be described by the chemical formula C3H7OH. One milliliter of isopropanol has a mass of 0.76 g, so its density is 0.76 g/mL. Isopropanol is often used as a cleaner or a disinfectant and evaporates when placed on warm objects. However, caution must be taken when using isopropanol, because it is also highly flammable. Which of the following is a chemical property of isopropanol?
A. One mL of isopropanol has a mass of 0.76 g.
B. Isopropanol has a density of 0.76 g/mL.
C. Isopropanol evaporates when placed on a warm object.
D. Isopropanol is flammable.
A chemical property of isopropanol : D. Isopropanol is flammable.
Further explanationThere are changes that occur in the mater: physical changes and chemical changes
Classification uses the principle of the initial and final state of the substance.
Physical changes do not form new substances, so the properties of the particles remain the same.(size,volume,shape)
Example : boiling and freezing, just change its phase form from liquid to gas or from liquid to solid
Chemical changes/reaction form new substances(products) that are different from the initial substances(reactants)
Example : toxic, corroded
So :
the physical properties of isopropanol :mass, density, evaporation
the chemical properties of isopropanol :highly flammable
Answer:
D. Isopropanol is flammable.
Explanation:
Mass, volume, temperature, phase of matter, color, texture, density, and hardness are all examples of physical properties. However, flammability is an example of a chemical property.
Chemical properties describe an object's potential to change its chemical composition. These properties depend on the types of atoms found in the object and the arrangement of those atoms (and their subatomic particles).
What is the mass of an object with a density of 5.7 g/cm^3 and a volume of 48
cm^3? *
Answer:
273.6 g
Explanation:
mass =(density)(volume)
mass=(5.7g/cm^3 )(48 cm^3)
cancel out your cm^3 and your are left with grams
multiply (5.7g)(48)=273.6 g
The mass of an object with a density of 5.7 g/cm³ and a volume of 48 cm³ is 273.6 grams.
What is density?Density is defined as the degree to which a material is packed together.
It is also defined as a mass per unit volume of the substance.
Its SI unit is kilogram per cubic meter or gram per meter.
Density can be expressed as
Density = mass / volume
Mass = density x volume
As given, Density = 5.7 g/cm³
Volume = 48 cm³
So, Mass = 5.7 g/cm³ x 48 cm³
= 273.6 grams
Thus, the mass of an object with a density of 5.7 g/cm³ and a volume of 48 cm³ is 273.6 grams.
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When many earthquakes are studied, there is another common pattern that emerges: a "Shadow Zone". This is an area, for any earthquake, on the Earth where direct S-waves don't arrive at all and P waves are refracted. What do you think causes these P waves to be refracted? *
Answer:
Sudden decrease in the velocity at the boundary.
Explanation:
The shadow zone is the zone of the earth from angular distances of 104° to 140° from a known earthquake that does not directly receive any P waves. Now, this shadow zone occurs as a result of S waves getting stopped completely by the liquid core and the P waves being refracted by the liquid core.
From earlier seismic discoveries, this boundary which is the shadow zone that does not directly receive any P-waves was found to be due to the fact that the P-waves were refracted inwards as a result of the sudden decrease in velocity at the boundary.
Which of the following elements would be brittle?
Sulfur
Magnesium
Rubidium
Lithium
Answer:
Sulfur
Explanation:
How do I do this problem???
Answer:
i believe it's c
Explanation:
my reason is that if you look at the electrons 2 is the most comm
what is the median number of 69,64,63,66?
During evaporation, what causes certain liquid molecules to become vapor molecules? A. Decreased fluidity A. Increased viscosity A. Decreased kinetic energy A. Increased kinetic energy.
Answer:
The answer is A. Decreased Fluidity
Explanation:
Taking the test on preformance matters
In evaporation, particles of liquids take energy in the form of sunlight from the surrounding and then convert into vapor phase. Increased kinetic energy causes certain liquid molecules to become vapor molecules.
What is evaporation?Evaporation is a physical process in which the water in liquid state converts to gaseous state at the temperature below its boiling point. Evaporation happens before the boiling process.
Evaporation causes cooling effect in the surrounding. During summer when water is kept in earthen pot water cools, this is because of the evaporation process.
Evaporation is affected by temperature. As the temperature increases, kinetic energy of liquid molecules also increases and hence the rate of evaporation increases.
Therefore, increased kinetic energy causes certain liquid molecules to become vapor molecules.
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How many moles are in 12.6 grams of K2S?