A student is attempting to identify an unknown liquid. She places 10 mL of the liquid in a test tube and begins heating it over a burner. She checks and records the temp every minute until it begins to boil. What is the independent variable?
Answer:
The time of heating
Explanation:
Let us analyse the experiment closely; the temperature of the liquid increases as the time of heating increases. This implies that the temperature of the liquid is dependent on the time of heating of the liquid. The longer the time of heating, the greater the increase in temperature until the boiling temperature is eventually attained.
Hence, the temperature of the liquid is the dependent variable, the time of heating is the independent variable when the heating rate is held constant.
which atom or ion is the largest?
A. K
B. K^+
C. Ca
D. CA^2+
E. Li
Answer:
A
Explanation:
3.04 Quiz: Chemical Reactions
Word bank please help fill.
Answer:
1. Chemical reactions
2.Substances
3. Properties
4. Precipitate
5. Light
6. Temperature
7. Color
8. Gas
Explanation:
During chemical reactions, new substances that possess new properties are formed. During the process of chemical reactions, evidences are found. Some of the evidences are formation of precipitate or light gel, production of gases and changes in colour and temperature.
Chemical reactions start with the substances or compounds which are known as reactants. The reactants react to form new substances known as the products which possess new properties.
Someone knows how to solve this? It was found that 0.0005 mol of Ca (OH) 2 dissolved in 100 cm3 of solution is 80% dissociated. Calculate the pH of this solution.
Answer:
pH = 11.9
Explanation:
First, we determine the number of OH⁻ moles dissolved:
80% of Ca(OH)₂ is dissolved:
0.0005 mol * 80/100 = 4x10⁻⁴ mol Ca(OH)₂There are two OH⁻ moles per Ca(OH)₂ mol:
4x10⁻⁴ * 2 = 8x10⁻⁴ mol OH⁻Now we can calculate the molar concentration of OH⁻ (moles/L):
100 cm³ = 100 mL100 mL ⇒ 100/1000 = 0.1 L[OH⁻] = 8x10⁻⁴ mol / 0.1 L = 8x10⁻³ MThen we calculate the pOH of the solution:
pOH = -log[OH⁻] = -log(8x10⁻³ M) = 2.10Finally, we can calculate the pH of the solution using the equation
pH + pOH = 14pH = 14 - pOH = 14 -2.10pH = 11.91 mol of titanium,
Ti, is 47.88 g is that true?
Answer: True.
Explanation:
Molar mass is the mass of a given substance divided by the amount of that substance, measured in g/mol. For example, the atomic mass of titanium is 47.88 amu or 47.88 g/mol. In 47.88 grams of titanium, there is one mole, or 6.022 x 1023 titanium atoms.
The characteristic molar mass of an element is simply the atomic mass in g/mol. However, molar mass can also be calculated by multiplying the atomic mass in amu by the molar mass constant (1 g/mol). To calculate the molar mass of a compound with multiple atoms, sum all the atomic mass of the constituent atoms.
For example, the molar mass of NaCl can be calculated for finding the atomic mass of sodium (22.99 g/mol) and the atomic mass of chlorine (35.45 g/mol) and combining them. The molar mass of NaCl is 58.44 g/mol.
HELP PLEASE ANSWER ASAP!!!!!
When atoms react, they often lose, gain, or share electrons to form a more stable version of themselves. For example, alkali metals such as sodium (Na) lose their outer shell electron in their reactions to form compounds. The electron configuration of alkali metals would then resemble those of which group of the periodic table in the compounds they form?
a. 7A or group 17
b. 8A or group 18
c. 2A or group 2
d. 1A or group 1
Answer:
D
Explanation:
A gas occupies a volume of 0.444 L at 0.00C and
79.00 kPa. What is the final Kelvin temperature when
the volume of the gas is changed to 1880. mL and the
pressure is changed to 38.70 kPa?
Include unit of measurement and use proper
significant figures.
Answer:
The final temperature is 566°K
Explanation:
Given
V1 = 0.444L
T1 = 0.00°C
P1 = 79.00 kPa
V2 = 1880mL
P2 = 38.70 kPa
Required
Determine the final temperature of the gas
To answer this, we make use of idea gas law equation.
This is:
(P1V1)/T1 = (P2V2)/T2
Convert V1 to mL
V1 = 0.444L
V1 = 0.444 * 1000mL
V1 = 444mL
Convert T1 to Kelvin
T1 = 0.00°C
T1 = 0.00 + 273K
T1 = 273K
Substitute these values in the given equation.
(P1V1)/T1 = (P2V2)/T2
(79 * 444)/273 = (38.70 * 1880)/T2
35076/273 = 72756/T2
Cross Multiply
35076 * T2 = 273 * 72756
35076T2 = 19862388
Make T2 the subject
T2 = 19862388 ÷ 35076
T2 = 566K (approximated)
Hence, the final temperature is 566°K
If 100 yards = 1 football field, what is the length, in meters, of 4.9
football fields?
Suppose someone claims they have invented a new automobile engine that can produce more energy than is found in the fuel used to run it. Apply scientific principles to evaluate the person's claim.
Answer:
See explanation
Explanation:
According to the second law of thermodynamics, the conversion of energy from one form to another is never hundred percent efficient. Some energy is always lost as energy is transformed from one form to another.
When a fuel is used to run an automobile engine, chemical energy from the fuel is converted into to the mechanical energy of the automobile. This energy conversion can never be hundred percent efficient in accordance with the laws of thermodynamics. Some energy is always lost as heat.
Hence, the engine does not even efficiently convert all the chemical energy available in the fuel. Therefore, it is impossible to find an automobile engine that can produce more energy than the fuel used to run it.
What reaction shows a compound breaking apart into separate substances?
Answer:
Explanation:
decompostion reaction
Which event most likely occurs at point V?
cooling
erosion
heating
melting
I will mark Brainlyest and 20 points
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Actually Welcome to the Concept of the Geography.
Answer is 1.) Cooling.
On cooling of magma, we get the hardened igneous rocks in the nature.
Answer:
Cooling
Explanation:
I did quiz
Why is it that no two elements have the exact same emission spectrum?
Answer:
When atoms are excited they emit light of certain wavelengths which correspond to different colors. Each element produces a unique set of spectral lines. Since no two elements emit the same spectral lines, elements can be identified by their line spectrum.
Explanation:
observe the long-term effects OT erosion on
1.
Click Play ( )). Wait for about 20,000 simulated years, then click Pause ( 1 ). If you want,
you can drag the landscape to rotate the view. How much does the landscape change?
Several erosive agents affect the soil structure and composition. Selecting sandstone, 100cm/yr precipitation, 20ºC, and 50% vegetation cover, there is 45% of eroded rock. The general landscape appearance changes little.
ErosionErosion is the process of fertile soil loss.
It is due to several external agents that damage the ground and drag the exposed material from the superficial layer of the earth.
Erosive agents
Some of the erosive agents are water, wind, ice, gravity, or animal trampling.
Phases
Three main phases compose the erosion process
a) particles landslide
b) transport of superficial free particles
c) deposit/sedimentation.
Soil erosion leads to its degradation.
Since its regeneration is extremely slow, erosion produces several negative events that lead to soil loss as a non-renewable natural resource.
Vegetation cover
All the erosive agents act together modifying the soil composition, shape, and structure. The loss of plant cover increases, even more, the erosive effects.
Soil vegetation cover reduces erosion because the aerial part of the plant protects the surface, while roots protect the ground structure and retain water.
The less vegetation cover there is, the more exposed the soil is, and the more severe effects the erosive agents cause.
In the exposed example, we have many variables to control and analyze their effect on soil erosion. Before playing the simulation, I chose the followings
Stones ⇒ sandstone Precipitation ⇒ 100 cm/yrTemperature ⇒20 ºCVegetation cover ⇒ 50%Under these conditions, after 20,000 years there was 0.42 km³ of eroded rock.
The general aspect of the landscape changed very little, suggesting that erosion occurs slowly.
Probably, if we change the values of the variables, we will observe a sharper change. For instance, if we take the vegetable cover to less than 20% and increase the levels of precipitation and temperature, we will observe a faster erosion process and a wider affected area.
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If he soundwave is producing sound with the steady pitch and is vibrating with a frequency of six waves per second then how many ways will be produced in four seconds
Answer:
n = 24 waves
Explanation:
As, the sound is produced with a steady pitch. Therefore, it means that there is no change in the pitch with respect to time. Hence, we can work with the following formula for frequency:
υ = n/t
where,
υ = frequency of sound wave = 6 waves/s
n = no. of waves = ?
t = time interval = 4 s
Therefore, using these values in the equation we get:
6 waves/s = n/4 s
n = (6 waves/s)(4 s)
n = 24 waves
Which element would have chemical reactions most similar to fluorine (F)?
A. O
B. Br
C. Ne
D. Fm
giving brainliest if right
[tex]\mathrm {Hey, there!}[/tex]
The answer is: Bromine
Oxygen is not similar to flourine, it is not a noble gas with high ionization.
Neon does not have chemical reactions like flourine.
The answer is Bromine! Best of Luck!
Answer:
Br
Explanation:
which of the following is the name given to the pairs of valence electrons that do not participate in bonding in diatomic oxygen molecule? A. unvalenced pair B. outer pair C. inner pair D. unshared pair
The name given to the pairs of valence electrons that do not participate in bonding in diatomic oxygen molecule is called Unshared pair
Unshared pair of electrons are also called Free radicals, lone pair or non bonding pairs, they refer to electrons that do not take part in covalent bonding of molecules.
Unshared pair together with shared pair occupy the valence electron shell and make up the valence electrons.
Diatomic oxygen molecule has 4 pair of unshared electrons
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Which of the following trends decrease down group 1 from Li → Cs?
I. melting point
II. jonization energy
III. atomic radius
A.
I and II only
B.
II and III
C.
II and IIl only
D.
I and III only
Answer:
A. I and II only
Explanation:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
Melting point also goes to decreases because there is large distance between the positive nucleus and bonded electrons thus overall attraction goes to reduced and less energy is required to melt.
Dry ice is a form of carbon dioxide that sublimates at room temperature. At a Halloween party, some students noticed that the dry ice underwent a phase change. Which statement below best describes the change in the energy and physical characteristics of the molecules of carbon dioxide during this process?
A. The molecules experienced a physical change from a gaseous state to a liquid state, releasing energy into the environment and reducing the molecular movement.
B. The molecules experienced a chemical change as the carbon dioxide reacted with oxygen, which released oxygen gas into the environment and increased the molecular movement.
C. The molecules experienced a physical change from a solid state to a gaseous state, which increased the molecular movement and the energy of the carbon dioxide molecules.
D. The molecules experienced a chemical change from a liquid state to a solid state, which reduced the amount of energy between the carbon dioxide molecules and decreased the molecular movement.
Answer:
The molecules experienced a physical change from a solid state to a gaseous state, which increased the molecular movement and the energy of the carbon dioxide molecules
brainliest
The statement which best describes the change in the energy and physical characteristics of the molecules of carbon dioxide during this process is (B) The molecules experienced a chemical change as the carbon dioxide reacted with oxygen, which released oxygen gas into the environment and increased the molecular movement.Hence, The correct option is (B)
What is Physical Change ?Physical changes are those that affect a chemical substance's form but not its chemical content.
Physical changes may normally be used to separate compounds into chemical elements or simpler compounds, but they cannot be used to separate mixtures into their component compounds.
A change in physical attributes accompanies a physical change. Melting, turning into a gas, and changing strength are a few examples of physical qualities.
Therefore, molecules of carbon dioxide during this process is (B) The molecules experienced a chemical change as the carbon dioxide reacted with oxygen, which released oxygen gas into the environment and increased the molecular movement.Hence, The correct option is (B)
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Question 1: The mixture that can be separated by filtration is:
a-iron and water.
b- salt and water.
c- vinegar and water.
Question 2: The solid remains on the filter paper is called:
a- filtrate.
b- distillate.
c- residue.
Question 3: The liquid that pass through the filter paper is called:
a-filtrate.
b-distillate.
c-residue.
Answer:
Filtration is a process in which insoluble matter is separated from a liquid. Filtration is a separation process in which a mixture is passed through a filter that allows one component to pass-through but blocks another component from passing through because of its matter and consistency. Heterogeneous mixtures can be separated into their respective constituents. For example, a mixture of mud and water can be separated through filtration process easily, because water being liquid will pass through the filter paper easily but the mud will not because of it being solid
Answer:
Q1 b.
Q2 a
Q3. b
Explanation:
filteration= separate solids from liquids or gases using a filter medium.
7 types of motion you experience through the day.
There is differ motion you go through the day translational, rotational, periodic, and non periodic motion.
Hope this helped you
Sorry if it wrong
When you have been swimming and you come out of the pool, you may feel cold. Use your understanding of endothermic processes to explain why?
Answer:
An endothermic process is any process with an increase in the enthalpy H (or internal energy U) of the system. In such a process, a closed system usually absorbs thermal energy from its surroundings, which is heat transfer into the system.
help me please!
Thermal energy can come from other forms of energy. Give several examples how.
i'm getting graded for this!!!
Which of the following is true about a hypothesis that is proven to be inaccurate? WILL GIVE BRAINLIEST FOR CORRECT ANSWER!!
A. An inaccurate hypothesis is not valuable.
B. It allows the scientist to eliminate any possibility of a relationship between two variables.
C. It will provide information to help formulate a new hypothesis in the future.
D. It proves that the exact opposite of the hypothesis is true.
Answer:
C. It Will Provide information to help formulate a new hypothesis in the future.
Explanation:
I had AP Chemistry.
The following statement that it will provide information to help formulate a new hypothesis in the future is true about a hypothesis that is proven to be inaccurate.
What is hypothesis?Hypothesis can be defined as an assumption which is made for the sake of argument . It is an interpretation of a practical condition for which action needs to be taken.It is defined as a tentative assumption which is made to test logical consequences.It is an antecedent clause of a statement which is conditional.
It is constructed before research. There are six types of hypothesis 1)simple hypothesis 2) complex hypothesis 3) directional hypothesis 4)non-directional hypothesis 5) null hypothesis 6)casual hypothesis
The hypothesis should be clear and precise, it must be specific and way of explanation of hypothesis should be simple.
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Which of these are significant problems with bottled water?
Immense plastic use
Fossil fuel used to transport water
Water bottles can leach toxics into water
All of the above
Answer:
All the above
Explanation:
All the above
How many moles are in 68 grams of copper (II) hydroxide, Cu(OH)2
heres your answer mate...
What mass of ethanol will release 410.0 J of heat when it cools
from 32.2°C to 19.1°C?
The specific heat of ethanol is 2.44 J/gºC.
12.8 g
(Don’t have explanation but it is right on CK-12)
Which bond is a very strong dipole-dipole force?
A. A covalent bond
B. An ionic bond
C. A hydrogen bond
D. A metallic bond
Answer : C. A hydrogen bond
Explanation:
Answer:
A. covalent bond
Explanation:
dipole-dipole interaction results from difference in electronegativity , eg H-F where Fluorine has strong electronegativity but Hydrogen has less electronegativity. hence the bond has dipole moment towards F atom.
Which term refers to the ability to do work? O energy O power force O motion
Please I have a 50 question Exam
Answer:
the correct answer in energy
Explanation:
The term refers to the ability to do work is energy. The correct option is A.
What is energy?Energy is the quantitative property that is required by the body to do some work. It is a conserved quantity, but can not be created or destroyed.
Animals and plants get energy from food.
Thus, the correct option is A. energy.
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Biologists designed an experiment to test the effect of compost on the development of root crops. They tested several different crops, including carrots, potatoes, beets, and onions. They grew most of the plants in the greenhouse, but due to space issues, they had to grow some outdoors. They gave all the plants the same amount of compost. They obtained the compost from a local farmer and from the local hardware store. They ran out of the farmer’s compost, so some of the plants received that compost when the seeds were planted and other plants got hardware store compost after the plants had already started growing.
RESULTS: Some of the roots seemed really big. Other roots seemed normal or small.
CONCLUSION: They couldn’t tell what the effect of the compost was because the results were inconsistent.
What are five problems with this experimental design that could have caused inconsistent results?
Answer:
it is 56
Explanation:
Answer:
one of the problems are that sum of the plants weren't getting the same kind of compost the second issue is that they couldn't fit all the plants into the greenhouse third issue issue was that some plants got compost when planted but what about the others
I got this answer from one of the WRONG answers. This was in the comments. So thanks to them!
What is the energy of the photons of a laser with a frequency of 5.75 x 10^12 Hz? (Hint: Remember to round your answer to the lowest number of significant figures.)
Planck's Constant =6.626 X 10^-34
Energy of a photon = Plancks constant x Frequency
Answer:
E = 3.81×10 ⁻²¹ J
Explanation:
Given data:
Frequency of photon = 5.75 ×10¹² Hz
Plancks constant = 6.626 ×10⁻³⁴ Js
Energy of photon = ?
Solution:
E = h×f
E = 6.626 ×10⁻³⁴ Js × 5.75 ×10¹² s⁻¹
E = 38.1×10 ⁻²² J
E = 3.81×10 ⁻²¹ J