Answer:
the answer is D
Explanation:
Conduction can only occur between two objects when – both objects are exactly the same temperature. Both objects are exactly the same temperature. One of the objects is made of a metal. One of the objects is made of a metal. Both objects are in physical contact with each other. Both objects are in physical contact with each other. One object is less dense than the other. One object is less dense than the other.
Answer:
Both objects are in physical contact with each other
Explanation:
Conduction refers to the flow of heat from one object to another when the both objects are in contact with each other.
Hence, before heat can flow from one object to another, the two objects must be in contact with each other. This is a key requirement before conduction can take place.
Calculate the mass (in g) of 2.1 x 1020 atoms of Os.
Answer:
here's the procedure to find it friend
Explanation:
How do you find the mass in grams of an atom?
In order to determine the mass of one atom of an element, you must determine its molar mass, which is its atomic weight on the periodic table in g/mol, and you need to know the relationship between moles and the number of atoms: 1 mol of atoms = 6.022×1023 atoms . Then divide the molar mass by 6.022×1023 atoms/mol .
is salt (NaCl) a base or a salt?
Answer:NaCl is a salt.
Explanation:
Answer:
It is salt
Explanation:
Calculate the molality of a saline solution in which 50.0 g of NaCl is dissolved in 0.750 kg of water.
Answer: Molality of a saline solution = 1.14 moles per kg
Explanation:
Given mass of NaCl (m)= 50.0 g
Mass of solvent = 0.750 kg
Molar mass of NaCl (M)= 23 g + 35.5 g = 58.5g [Atomic mass of Na = 23 u , atomic mass of Cl = 35.5 u]
Number of moles (n) =[tex]\dfrac{m}{M}[/tex]
[tex]\dfrac{50}{58.5}=.8547[/tex]
Molality = [tex]\dfrac{\text{Number of moles }}{\text{Mass of solvent in kg}}[/tex]
[tex]=\dfrac{0.8547}{0.750}=1.1396\approx1.14\text{ moles per kg][/tex]
Hence, molality of a saline solution = 1.14 moles per kg
A 22.5 mL sample of liquid ethanol (C₂H₅OH, density = 0.789 g/mL) was injected into a 10.0 L cylinder containing O₂ at a pressure of 4.50 atm and a temperature of 25°C. The cylinder was heated to 125°C and a spark was used to ignite the ethanol, which was completely combusted. What was the final total pressure in the cylinder (in atm) after the reaction, while it was still at 125°C?
Answer:
The final total pressure in the cylinder = 8.53 atm
Explanation:
From the information given:
The volume of liquid ethanol = 22.5 mL
The density of the liquid ethanol = 0.789 g/mL
The volume of the cylinder = 10.0 L
The pressure of the cylinder = 4.50 atm
The temperature of the cylinder = 25°C = (273.15 + 25) K = 298.15 K
Using the ideal gas equation:
PV = nRT
where n is the number of moles before the reaction:
[tex]n = \dfrac{PV}{RT}[/tex]
[tex]n = \dfrac{4.5 \ \times 10 }{0.08205 \times 298.15}[/tex]
n = 1.8395 moles
Recall that:
Density = mass /volume
Thus; the mass of liquid ethanol = (Density × volume ) of liquid ethanol
the mass of liquid ethanol = 0.789g/mL × 22.5 mL
the mass of liquid ethanol = 17.7525 g
Since we know the mass of the liquid ethanol = 17.7525 g and the standard molar mass of liquid ethanol = 46.07 g/mol
Then:
the number of moles of liquid ethanol = 17.7525 g / 46.07 g/mol
the number of moles of liquid ethanol = 0.38534 mol
The chemical equation for the reaction can be represented as:
[tex]C_2H_5OH + 3O_2 \to 2CO_{2(g)} + 3H_2O_{(g)}[/tex]
From above 1 mole of ethanol react with 3 moles of oxygen to produce 2 moles of carbon dioxide and 3 moles of water
Since each mole of ethanol reacts with 3 moles of oxygen
Then:
0.38534 mol of ethanol = (0.38534 mol × 3) oxygen
Therefore, the amount of oxygen molecule left in the cylinder after the reaction = 1.8395 mol - (0.38534 mol × 3)
= 1.8395 mol - 1.15602 mol
= 0.68348 mol
The number of moles of carbon dioxide formed = 2 × moles of ethanol
number of moles of carbon dioxide formed = 2 × 0.38534 mol
number of moles of carbon dioxide formed = 0.77068 mol
The number of moles of water vapour formed = 3 × 0.38534 mol
The number of moles of water vapour formed = 1.15602 mol
∴
The total moles of gas = moles of oxygen left + moles of water vapour + moles of carbon dioxide
The total moles of gas = 0.68348 mol + 0.77068 mol + 1.15602 mol
The total moles of gas = 2.61018 mol
Finally, to find the total pressure in the cylinder when the temperature is 125°C = (273.15 + 125)K
= 398.15 K
Then; using the ideal gas equation PV = nRT
P = nRT/V
P = ( 2.61018 × 0.08205 × 398.15 ) / 10
P = 85.2699/10
P = 8.52699 atm
P ≅ 8.53 atm
.apclassroom college board org / . OollegeBeard AP Classroom Unit 3 FRO Test d. Based on concepts of atomic structure and periodicity, propose a modification form between halogens and fluorine B a. CIF a T-shaped structure is asymmetric with dipoles that do not cancel out but produce
a. The atomic size of fluorine is very small compared to other halogens. Similarly, fluorine is the highest electronegative atom in periodic table. b. CIF a T-shaped structure is asymmetric with dipoles that do not cancel out but produce a net dipole.
What is dipole moment ?In a compound with atoms of significant difference in electronegativities, the shared pair of electrons attracts towards the more electronegative atom and this results in a charge separation. The measure of the separation of two electrical charges is called the dipole moment of the compound.
a. Fluorine is the most electronegative atom in periodic table. Compared to other halogens, F has very small atom and have less electron affinity compared to other halogens.
b. Cl - F is an interhalogen compound in which dipole moment is created by the electronegativity difference between Cl and F. The net dipole moment is towards the F atom.
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An ionic bond is held together by an electrostatic between what two types of elements?
metal and nonmetal atom
metal atoms only
cations
nonmetal atoms only
In 20 words or fewer, explain why the statement "Dropped objects fall
toward the ground" is a law and not a theory.
Answer:
The statement is a description of something that happens, not an explanation of why it happens.
Explanation:
A px
The statement "Dropped objects fall toward the ground" is a law and not a theory given by Newton sir as he was sitting under s tree and apple falls on the earth which he observed and gravity is observed from there only.
What is the gravity?The gravity is the strongest force of attraction between the surface of the earth and in the each substance or object present on the earth.
According to the law of Newton sir the gravitational force of the earth depends on the mass of the object if the mass of object is double then the gravitational force of the earth is also double.
Therefore, statement "Dropped objects fall toward the ground" is a law and not a theory given by Newton sir as he was sitting under s tree and apple falls on the earth which he observed and gravity is observed from there only.
Learn more about gravity, here:
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what is dilution law
Answer:
Please Mark as Brainliest!!!!!!!
Explanation:
Answer is in the below image
Everything that you can touch and feel is made up of
Answer:
matter/mass is made up of anything you see touch and fell
Which has a larger ionic radius than it's neutral atom?
Chlorine
Aluminum
Sodium
Magnesium
Answer:
sodium??
Explanation:
A man is making a metallic gate for their new house. What will the man do in order for his gate to prevent rusting?
Answer:
to prevent rust the man should oil his get or use lubricants to lubricate it
Which of the following is the correct equation for calculating SPEED?
Answer:
Where is the following?
Explanation:
The formula for speed is speed = distance ÷ time. To work out what the units are for speed, you need to know the units for distance and time. In this example, distance is in meters (m) and time is in seconds (s), so the units will be in meters per second (m/s).
Answer:
Speed = Distance / Time
Explanation:
Distance = Speed * Time
Time = Distance / Speed
Use this chart to help you remember. Cover what you don't have. If it is next to each other, multiply. If one is on top, divide what is on top with the one on the bottom.
Identify two life functions involved in meeting the energy demands of a cell or an organism.
Answer:
digestion and respiration
Answer:
I think the answer is: Cell
Explanation:
im not sure but i think its cell
How do we know the Earth is approximately 4.6 billion years old?
Which science is the study of living organisms?
PLES NEED HELP asap
chemistry
physics
biology
astronomy
Answer:
Biology
Explanation:
Answer:biology
Explanation:
Which of the following is an example of
positive feedback?
A Regulation of blood glucose levels
B Regulation of body temperature
C Contractions in childbirth
Answer:
Regulation of body temperature
Explanation:
Should the characteristics of life be redefined? Why and why not
Answer:
Ok audry vamos a esto,Si eso pasa,Los viruses dejaran de infectar o será peor? Si se redefina las características de la vida,Nos adaptarianos rapido?Que ganamos con cambiar eso? porque se debe de cambiar?
Ok audry let's get to this, if that happens, will the viruses stop infecting or will it be worse? If we redefine the characteristics of life, we adapt quickly? What do we gain by changing that? why should it be changed?
Explanation:
esas son las preguntas que tienes que hacer a ver si hace sentido el cambio que quieren hacer porque de que vale hacer un cambio sin saber si nos va a beneficiar o no O si eso va a resolver el conflicto. (is me lorenny XD )
Those are the questions that you have to ask to see if the change they want to make makes sense because of what is worth making a change without knowing if it will benefit us or not or if it will resolve the conflict. (is me lorenny XD)
Will give brainliest please give me the Lewis model of Magnesium sulfide
Answer:
The Lewis dot structure for Magnesium is an Mg with 2 dots which stand for its two valence electrons. The Lewis dot structure for Sulfur is an S with 6 dots which stand for its six valence electrons. ... The Magnesium atom has a +2 charge and the Sulfur atom has a -2 charge.
Explanation:
How many kilograms are in 1256.55 centiliters?
Answer:
12.5655
Explanation:
divide by 100
Answer:
12.5655
Explanation:
To find the answer you need to move the decimal place left two times <3
How many seconds are in 30 days?
explain how gravity will affect the growth of the plant's stem and roots
Answer:
Honestly this is the first question I’m stumped on
Explanation:
Answer:
Plants respond directly to Earth's gravitational attraction, and also to light. Stems grow upward, or away from the center of Earth, and towards light. Roots grow downward, or towards the center of Earth, and away from light. This process turns the stem so that it once again grows upward, presumably toward the light.
Explanation:
Which elements are least easily identified? Explain-
Answer:
hydrogen
oxygen
hydrogen is easily identified by a any liqiud substance
hydrogen=liquid
oxygen is also easily identified by air
oxygen=air
How does the periodic table help to determine the number of valence electrons for an element?
Answer:
valence electrons are determine by the numbers at the top of the grop so group 1 has 1 valence electron, group 2 has 2 valence electrons, groups 3-12 have no valence electrons, group 13 has 3 valence electrons, group 14 has 4 valence electrons, group 15 has 5 valence electrons, group 16 has 6 valence electrons, group 17 has 7 valence electrons and group 18 has 8 valence electrons exept helium. helium has 2 valence electrons.
Explanation:
Help fast this is my last question I have to do
Which biomes would be found nearest to the equator
Explanation:
found near the equator usually is the tropical forest
Answer:
Tropical rain forests and savannas
Explanation:
Did the test on Edge 2021
What is the difference between a single atom and a molecule?
Answer:
Atoms are single neutral particles.
Molecules are neutral particles made of two or more atoms bonded together.
Answer:
a molecule is made up of atoms bonded together so while an atom is its own separate entity a molecule is what you get when those atoms bond together. these might be the same elements such as two oxygen Atoms bonded together (O2), or it might be different Atoms bonded together like water(H20)
what energy is usually associated with bond formation?
Water is formed when 48g of oxygen combine with 6g of hydrogen. What mass of oxygen combines with 2g of hydrogen?
A. 12g
B. 16g
C. 96g
D. 144g
Answer:
B. 16g
Explanation:
What are two units that are used to measure volume in chemistry?
Answer:
The mass of water is expressed in grams (g) or kilograms (kg), and the volume is measured in liters (L), cubic centimeters (cm3), or milliliters (mL). Density is calculated by the dividing the mass by the volume, so that density is measured as units of mass/volume, often g/mL.