Answer:
Explanation:
Which of the following best describes weather? day to day conditions of the atmosphere at a place in regards to heat, dryness, sunshine, wind, rain, etc. long-term conditions (30 or more years) of the atmosphere at a place in regards to heat, dryness, sunshine, wind, rain, etc.
Answer:
Weather is short term climate is long term.
Explanation:
What is the weight of:
i) 1 mole of oxygen atoms?
ii)
i) 3 moles of iron atoms?
3 ?
iii) 20 moles of calcium carbonate?
Answer:
Oxygen = 15.999 g/mol
Iron = 3 × 55.845 = 167.535 g/mol
CaCO3 = 20 × 100.0869 = 2001.738 g/mol
Name the element in the second period of the periodic table with 6 valence electrons.
Answer:
Sulfur
Explanation:
Using this to make the answer 20 characters long
A student would like to determine how heating a liquid changes its volume. The student hypothesizes that the liquid will increase in volume. The following list shows the steps taken by the student in order to test the hypothesis.
1.Select the liquid to test.
2.Place the liquid in a sealed container.
3.Use a Bunsen burner to heat the liquid by 10°C.
4.Measure the volume of the liquid.
5.Record the results.
What is wrong with how the student conducted the investigation?
A.
The hypothesis was not valid because it is impossible for liquids to change in volume.
B.
The volume of the liquid should be measured before it is heated.
C.
The student should have increased the temperature of the liquid by more than 10ºC.
D.
The length of time it took for the liquid to be heated should be measured.
Answer:
The volume of the liquid should be measured before it is heated.
Explanation:
Because During an experiment to test how a variable changes a substance, it is important to first observe and record the characteristics of the substance before the variable is introduced. In this case, the variable is heat energy.
why the table perdioc has 3 columns in its group 8 ,
i need reference about that please
Answer: It just haven’t been discovered yet
Explanation:
Because the periodic table was discovered long ago some elements haven’t been discovered thats why it maybe has 3 columns
How is melting simillar evaporation
Answer:
Melting and evaporation both represent changes in matter that involve behavior at the molecular level.
Answer:
well both disappear over time
Explanation:
What mass of LiOH would need to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40
Taking into account the definition of pH and pOH, the mass of LiOH needed to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40 is 0.299375 grams.
First of all, pH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.
The pH is defined as the negative base 10 logarithm of the activity of hydrogen ions, that is, the concentration of hydrogen ions or H₃O⁺:
pH= - log [H⁺]= - log [H₃O⁺]
Similarly, pOH is a measure of hydroxyl ions in a solution and is expressed as the logarithm of the concentration of OH⁻ ions, with the sign changed:
pOH= - log [OH⁻]
The following relationship can be established between pH and pOH:
pOH + pH= 14
In this case, being pH= 12.40, pOH is calculated as:
pOH + 12.40= 14
pOH= 14 - 12.40
pOH= 1.60
Replacing in the definition of pOH the concentration of OH⁻ ions is obtained:
- log [OH⁻]= 1.60
Solving:
[OH⁻]= 10⁻¹ ⁶
[OH⁻]= 0.025 M
Then, the [OH⁻] is 0.025 M.
Strong bases are bases that completely dissociate in water into the cation and OH - (hydroxide ion). LiOH is a strong base, so the OH- concentration is equal to the LiOH concentration:
[OH⁻]= [LiOH]= 0.025 M
Finally, Molarity or Molar Concentration is the number of moles of solute that are dissolved in a certain volume:
[tex]Molarity=\frac{number of moles}{volume}[/tex]
In this case, knowing that molarity is 0.025 M and the volume is 500 mL= 0.5 L, you can replace in the expression for molarity:
[tex]0.025 M=\frac{number of moles}{0.5 L}[/tex]
Solving:
number of moles= 0.025 M× 0.5 L
number of moles= 0.0125 moles
Finally, since the molar mass of LiOH is 23.95 [tex]\frac{g}{mol}[/tex], that is, the amount of mass that the substance contains in one mole, the mass of LiOH that 0.0125 mol contains can be calculated as:
0.0125 mol×23.95 [tex]\frac{g}{mol}[/tex]= 0.299375 g
The mass of LiOH needed to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40 is 0.299375 grams.
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https://brainly.com/question/12200689brainly.com/question/16032912?referrer=searchResultsbrainly.com/question/13557815?referrer=searchResultsA fruit-and-oatmeal bar contains 142 nutritional Calories. Convert this energy to calories
Answer:
a fruit and oatmeal bar contains 142000 calories.
A nutritional calorie, or kilocalorie, is equal to 1000 calories.
E = 142 kcal · 1000 cal/kcal.
E = 142 000 cal.
Calorie (cal), or small calorie, is the amount of energy needed to heat one gram of water by one degree Celsius.
One small calorie is approximately 4.2 joules.
A calorie is a unit of energy.
Explanation:
hope it helps :)
Record your observations.
8th grade k12 science
how many chemical bonds are formed in CH4 molecule
Answer:
4 covalent bonds
How much is 1 mole of something?
O A. 6.02 x 10
O B. 6.02 x 10-23
O C. 6.02 × 23
O D. 6.02 x 1023
Answer:
see explanation
Explanation:
How much is 1 mole of something?
O A. 6.02 x 10
O B. 6.02 x 10-23
O C. 6.02 × 23
O D. 6.02 x 1023
look carefully at your picture
use a magnifying glass if you need to
I am rewriting the choices the way it appears i your picture
A. 6.02 X 10
B 6.02 X 10^-23
C. 6.02^23
D. 6.02 X 10^23
the answer is D. you left out "to the pow......"
a significant mistake
what is in your picture is 6.02 X 10^23 and means
6.02 X 100,000,000,000,000,000,000,000
what you wrote 6.02 X 1023 means 6158
when we are talking about the number of teensy tiny atoms in a measurable mass we are talking BIGGGGG GIANTTTTT numberswhen written correctly, the answer is D
The organelle is found in plant cells contains a green pigment and is the site of photosynthesis. this organelle is the _______
Answer: Chloroplast
Explanation:
The specific heat of a certain type of cooking oil is 1.75J(g. °C). How much heat energy is needed to raise the temperature of 2.44 kg of this oil from 23. °C to 191 °C?
Answer:
The amount of heat needed is 593.88 kJ.
Which candle burned the longest time why
Answer:
The one that burned longer because it burned longer
Explanation:
THE POINT (-7,4) IS REFLECTED OVER THE LINE X=-3. THEN, THE RESULTING POINT IS REFLECTED OVER THE LINE Y=X. WHERE IS THE POINT LOCATED AFTER BOTH REFLECTIONS?
Answer: 4,2
The graph should show how to do it.
are ions always smaller than their neutral atoms
Answer:
The negative ion is larger than the original atom. but the same number of positive protons, the size of the ionic radius will increase. When an atom has its electrons attracted to another atom it becomes a positive ion. The positive ion is smaller than the original atom.
To determine the heat of neutralisation, Chelsea placed 50 cm' of sodium hydroxide
solution of concentration 1.0 mol dm- in a polystyrene cup and recorded its
temperature. She then recorded the temperature of 50 cm of sulfuric acid, added it
to the cup, stirred the solution and recorded its maximum temperature, as follows:
. initial temperature of NaOH(aq) = 29.5 °C
. initial temperature of H.SO, (aq) = 29.9 °C
• maximum temperature of the solution = 35.8 °C
Calculate the increase in temperature
2 solutions of NaOH and H₂SO₄ at 29.5 °C are mixed in a coffee-cup calorimeter and after the reaction is completed the temperature is 35.8 °C. The increase in the temperature is 6.3 °C.
To determine the heat of neutralization, Chelsea used a coffee-cup calorimeter.
Initially, she had 2 solutions, NaOH and H₂SO₄, both at 29.5 °C. Upon mixing, the heat was evolved and the final temperature of the solution was 35.8 °C. The neutralization reaction was:
NaOH + H₂SO₄ ⇒ Na₂SO₄ + H₂O
The increase in temperature (ΔT) is equal to the difference between the final temperature and the initial temperature.
[tex]\Delta T = 35.8 \° C - 29.5 \° C = 6.3 \° C[/tex]
This data can be used to calculate the heat of neutralization (q) using the following expression.
[tex]q = c \times m \times \Delta T[/tex]
where,
c is the specific heat capacity of the solutionm is the mass of the solution2 solutions of NaOH and H₂SO₄ at 29.5 °C are mixed in a coffee-cup calorimeter and after the reaction is completed the temperature is 35.8 °C. The increase in the temperature is 6.3 °C.
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When the volume of a closed container containing hydrogen gas is increased by a factor of two, how will this affect the number of hydrogen atoms in the container
We have that for the Question "When the volume of a closed container containing hydrogen gas is increased by a factor of two, how will this affect the number of hydrogen atoms in the container"
Answer:
Number of hydrogen atoms depend only on amount of gas which remains constant. Hence, increasing the volume of container has no affect on number of hydrogen atoms.Explanation:
The number of hydrogen atoms will remain the same in the container. Because the container is closed and amount of hydrogen gas remains constant, which means that no extra amount of hydrogen gas is removed or added from the container when volume increases.
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T("C) = 2
T, ("C) =
AT ("C) =
(J/g °C) = 3.77
M(9) = 340g
(J) = 10,000
what is the change in temperature? And what is the final temperature?
Answer:
1.377
Explanation:
Because we are subtract the initial from the final
What is an example of microorganisms acting in a harmful way?
Answer:
Mark me as brainlest
Explanation:
Microorganisms present in our body Re viruses, bacteria, fungi, algae, and protozoa among which most of them cause immense benefits to the body. There are some harmful microorganisms too known as pathogens which cause disease and cause a threat to all existing life forms of the earth which can result in death at times.
Answer:
An example of microorganisms acting in a harmful way is a bacteria spoiling food.
Using the bond energies provided, calculate the enthalpy of the reaction (∆Hrxn, in kJ) for the hydrogenation of propene to propane, shown below?
CH₂CHCH₃(g) + H₂(g) → CH₃CH₂CH₃(g)
The enthalpy of reaction for the hydrogenation of propene to propane is -926 kJ/mol.
The bond energy of a molecule is obtained as the sum of the bond energies of all the bonds between atoms in the molecule. The heat of reaction can be obtained using the relation;
∆Hrxn = ∑Bonds being broken - ∑Bonds being formed
Hence, we have;
Where all the energies are quoted in KJ/mol
C=C = 598
C - C = 346
H - H = 436
C - H = 416
For the reaction;
CH₂CHCH₃(g) + H₂(g) → CH₃CH₂CH₃(g)
∆Hrxn = ∑[6(C - H) + 1(C=C) + 1(C - C)] - ∑[3(C - C) + 8(C - H)
∆Hrxn = [6(416) + 1(598) + 1(346)] - [3(346) + 8(416)]
∆Hrxn =3440 - 4366 = -926 kJ/mol
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What is the density of an object that has a mass of 1.08 kg and displaces 50.50 cm3 of water? (Please report your answer in g/cm3 ) Please report your answer in decimal notation not scientific notation the computer will mark it incorrect.
Answer:
Explanation:
1.08kg/50.5 cm^3(1000g/kg)=21.386 g/cm^3
Answer:
[tex]\boxed {\boxed {\sf 21.4 \ g/cm^3}}[/tex]
Explanation:
We are asked to find the density of an object.
The density of a substance is its mass per unit volume. It is calculated by dividing the mass by the volume.
[tex]\rho= \frac{m}{v}[/tex]
The mass of the object is 1.08 kilograms. The object displaced 50.50 cubic centimeters of water, so this value is its volume.
We are asked to give the density in grams per cubic centimeter, so we must convert the mass. There are 1000 grams in 1 kilogram. Set up a conversion factor.
[tex]\frac {1000 \ g}{1 \ kg}[/tex]
Multiply by the given mass: 1.08 kg
[tex]1.08\ kg *\frac{1000 \ g }{ 1\ kg}[/tex]
The units of kilograms cancel.
[tex]1.08*\frac{1000 \ g }{1}[/tex]
[tex]1.08*{1000 \ g } = 1080 \ g[/tex]
Now we know the mass in grams and the volume:
m= 1080 g v= 50.50 cm³Substitute the values into the density formula.
[tex]\rho= \frac{1080 \ g }{50.50 \ cm^3}[/tex]
Divide.
[tex]\rho= 21.3861386 \ g/cm^3[/tex]
The original measurements of mass and density have 3 and 4 significant figures. Our answer must have the least number of significant figures, or 3.
For the number we found, that is the tenths place. The 8 in the hundredth place tells us to round the 3 in the tenths place up to a 4.
[tex]\rho \approx 21.4 \ g/cm^3[/tex]
The density of the object is approximately 21.4 grams per cubic centimeter.
Which correctly describes the lithosphere? *
A.The crust and the upper part of the core
B.The crust and the upper part of the ocean
C.The crust and the upper part of the mantle
D.The core and the upper part of the mantle
Answer:
its for sure not b. its c the crust and upper part of the mantle.
the whole definition:
the rigid outer part of the earth, consisting of the crust and upper mantle.
An element with 7 valence electrons would be a
O + 7 cation
0 - 1 anion
0 - 7 cation
O + 1 anion
Answer:
The Group 7A elements have seven valence electrons in their highest-energy orbitals (ns2np5). This is one electron away from having a full octet of eight electrons, so these elements tend to form anions having -1 charges, known as halides: fluoride, F-; chloride, Cl-, bromide, Br-, and iodide, I-.
...
Group 7A — The Halogens.
(7)
(8)
(9)
(10)
Explanation:
here is your answer hope you will enjoy and mark me as brainlist
thank you
PLEASE HELP ASAPPPPPP
Answer:
accelerating upward would be your answer
What best describes the transition from gas to liquid
It's condensation in which gas particles have a higher kinetic energy..
Which statement correctly explains how matter is conserved in chemical reactions? (1 point)
Answer:
can you include the choices?
Explanation:
Answer:
Answer b: The law of conservation of matter says that in chemical reactions, the total mass of the products must equal the total mass of the reactants.
Explanation:
hope this helps
Which is not an example of vaporization?
Answer:
boi i need the choices idiot
Explanation:
Nobody can add an answer without context.
But if this helps,
"Vaporization of an element or compound is a phase transition from the liquid phase to vapour. There are two types of vaporization: evaporation and boiling. Evaporation is a surface phenomenon, whereas boiling is a bulk phenomenon." - Wikipedia
https://en.wikipedia.org/wiki/Vaporization
Sugar 2C6H1206 total number of atoms *
Answer:
6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms
Explanation:
If 20.3 g of NO and 13.8 g of O₂ are used to form NO₂, how many moles of excess reactant will be left over?
2 NO (g) + O₂ (g) → 2 NO₂ (g)
Answer:
0.02 moles of O₂ will be leftover.
Explanation:
What is the numerical value of the standard entropy change of formation, delta S degree, for BrCl(g) at 298 K
Answer:
B)
Explanation:
