Auroras present in polar regions.
Answer:
the Northern Lights
Explanation:
The northern lights, one of several astronomical phenomena called polar lights (aurora polaris), are shafts or curtains of colored light visible on occasion in the night sky. Aurora borealis
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A chemical reaction involving substances a and b stops when b is completely used. B is the.
I NEED HELP QUICK!! what is the equation to find the percent composition of NaHCO3????
Answer:
???????????
Explanation:
Dense, definite shape, definite volume, not compressible....are properties of
Group of answer choices
gas
liquid
solid
Answer:
Solid
Explanation:
Gas and liquids cant have definite shape which should be crossed off after you read shape because gas goes everywhere and liquids are too runny
What method is used for chaff from grain
Answer:
Winnowing
Explanation:
Wind blows the lighter(in terms of mass) chaff from the whole grains,which are heavier(in terms of mass)
Compare blue and violet light. which one has the highest energy?
Longest wavelength?
Answer:
Blue
Explanation:
Blue would have the longest wave length because following ROY G BIV the wave length distance between the two decreases as you move from Red to Violet.
Which statement does not describe an independent variable? *............A......The responding variable........B.........The part that is changed by the scientist...........C.........The factor being manipulated..........D............The part of the experiment being tested
Answer:
The responding variable
Explanation:
The independent variable in a study refers to the factor that is being manipulated in an experiment.
As the independent variable is changed, its effect on the responding (dependent) variable is accessed.
The responding variable changes as the independent variable is manipulated, they do not mean the same thing.
please help , i’m doing a test and i’m really bad at science , lol , thank you !
it cannot be passed to the next generation meaning A chromosome will be eliminated
how many significant figures does 0.00003 have?
What is the formula unit for a compound made from Pb4+ and oxygen? (3 points)
PbO2
O2Pb
Pb4O2
O4Pb2
The formula unit of compound made up from Pb4+ and oxygen is PbO2.
The formula unit for a compound made from Pb⁴⁺ and oxygen is PbO₂. Therefore, option (1) is correct.
What is the formula unit?A formula unit represents the lowest whole number ratio of ions in an ionic compound. The formula mass of a substance is the sum of the atomic masses of the ions present in the formula unit of an ionic compound.
Formula unit is the empirical formula of any covalent or ionic solid compound which is used as an independent entity for stoichiometric calculations. Formula mass is also defined as the sum of atomic masses of constituent atoms in an ionic compound.
A molecule is made up of two or more elements that are covalently bonded. Also, the molecular mass gives the mass of a molecule relative to that of a carbon twelve atom which has a mass of twelve units.
As we know the valency of lead is 4 and the valency of oxygen is 2. To satisfy the valency of each other two oxygen combine with one lead (IV). Therefore, the formula unit of the compound is PbO₂.
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Please help me with this sheet this is science
A force is an agent that causes a change in the shape or state of motion of an object.
Forces such as gravity, helps keep objects on earth's surface.
What is a force?A force is a pull or push agent which causes a change in the shape or motion of a body.
Forces may or may not result in motion.
Forces can change the position, shape and movement of an object but not its color.
Types of forces include:
frictiongravitymagnetismFriction is a force that slows or stops the motion of an object.
Magnetism is a force is that attracts objects mad of steel, nickel, or cobalt.
Gravity is a force that pulls objects to the centre of the earth.
Example of a pushing force is pushing a car.
Example of pulling force is closing a car door.
Due to the gravitational force acting on all bodies on the earth surface, we do not fall off the earth.
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an open flame from a burner heats up the inside of a balloon, allowing it to take flight. How is the pilot able to control the altitude of the balloon.
Answer:
The direction of flight depends on the wind, but the altitude of the balloon can be controlled by changing the temperature of the air inside the envelope. the pilot controls the ascent of the balloon.
Explanation:
:)
Hi how are you
what do you think about this
Why is it important for us to show demonstrations and give evidence for our scientific claims?
Please help me this is due today!!!!
Answer:
Well first, a scientific claim is claims or statements after experimenting. Similar to other claims but they have evidence and data to support the claim.
So we would show demonstrations because we need support our scientific claim.
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I think the answer will be:
C. Increase the rate forward and reverse reactions equally.
Select the correct answer. Which sentence is true of all Brønsted-Lowry bases? A. They can donate a hydrogen ion. B. They can accept a hydrogen ion. C. They can produce hydronium. D. They are positively charged. E. They are negatively charged.
Bronsted - Lowry base can accept a hydrogen ion and can produce hydronium.
What are bases?Bases have the pH value in between the range of 7 to 14.
According to the Bronsted - Lowry theory of acid & base, those substance which produces H⁺ ion or proton in the aqueous medium are known as acids and those substance which accepts the H⁺ ion or proton in the aqueous medium are bases. Water is also behave as Bronsted - Lowry base as it accepts the H⁺ ion and forms hydronium ion H₃O⁺.
Hence, option (b) & (c) are correct, i.e. They can accept a hydrogen ion and produce hydronium.
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NEED HELP ASAP
How can you dissolve more sugar in your coffee, more quickly? In answering this question:
Identify the solute and solvent in the resulting solution
Describe ways to make the sugar dissolve more quickly
Indicate how to maximize the amount of sugar that can be added
Answer:
the solvent =water+coffee powder
the solute =sugar
Explanation:
Breaking up, crushing or grinding a sugar cube before adding it to water increases the sugar's surface area. The more surface area a solute has, the faster it will dissolve because more particles of the sugar can interact with the water. This means the finer the sugar particles meaning a larger surface area which leads to an increase in a faster reaction
When did the water level in Lake Mead become a concern?
Answer:
in 1983, Lake Mead had a recorded water level of 1,225 feet above sea level. The closest it's been to that level in modern times was in 2000. Explanation:
A sample of gas in a rigid container at 1.30 atm and 224 K is heated to 815
K. Assuming that the volume remains constant, what will be the new
pressure of the gas?
With a container at 1.30 atm and 224 K is heated to 815k, the new
the pressure of the gas is mathematically given as
P=4.7299atm
What will be the new pressure of the gas?Question Parameter(s):
A sample of gas in a rigid container at 1.30 atm and 224 K is heated to 815
K.
Generally, the equation for the Ideal gas is mathematically given as
P1/T1=P2/T2
Therefore
1.30/224=P2/815
P=4.7299
In conclusion, new the pressure
P=4.7299atm
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how can hot water freeze faster then cold water.
Answer:
With the cooler water at the bottom, this uneven temperature distribution creates convection currents that accelerate the cooling process. Even with more ground to cover to freeze, the temperature of the hotter water can drop at a faster rate than the cooler water.
Explanation:
What four factors influence the rate of a homogeneous reaction.
Reactant concentration, the physical state of the reactants, surface area, temperature, and the presence of a catalyst are the four factors to influence the rate of a homogeneous reaction.
What is rate of reaction ?The term rate of reaction is defined as the speed at which a chemical reaction takes place. It is also defined as proportional to the increase in the concentration of a product per unit time and to the decrease in the concentration of a reactant per unit time.
Surface area, greater surface area, more collisions are available and then concentration, when increase the concentration then increase the likelihood of reactants colliding. Catalysts increase reaction without itself getting used up.
Thus, The factors to influence the rate of a homogeneous reaction are Reactant concentration, the physical state of the reactants, surface area, temperature, and the presence of a catalyst.
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what happens when calcium is treated with water?
form calcium hydroxide and hydrogen gas
Ca + 2H₂O ⇒ Ca(OH)₂ +H₂
True/false: An object acceleration depends on its mass and force. Need help ASAP
Which statement describes a chemical property of mercury?
A. Mercury bonds with oxygen to form a compound found in some
batteries.
B. Mercury is the only metal that is liquid at room temperature.
C. Mercury is much denser than water, so it will sink in water.
D. Mercury is a shiny, silver substance that is found in some
thermometers.
Answer:
It's A
Explanation:
I took the test. For A p e x
Which of the following best describes what led to London’s ""killer fog"" in 1952? a. Pollution from the air contaminated the water supply which is what killed people. B. Millions of coal fires and stagnant air caused toxic fumes to build up in the air. C. Poor city design led to faulty ventilation in houses. D. Soot from forest and wildfires in the surrounding areas blew over the city. Please select the best answer from the choices provided A B C D.
London’s "killer fog" or The Great Smog of London was the extreme event of air pollution in London. Millions of coal fires and stagnant air were the prime reason for the event.
What was The Great Smog of London?The Great Smog of London was one of the worst events of the air pollution that engulfed the city of England. The industrial air pollutants of the burning coal and high-pressure weather circumstances made the city covered in smog.
This event caused many deaths due to pneumonia and bronchitis in people. The burning of the coal in the industrial plants of the city was the major reason for the smog.
Therefore, option B. millions of coal fires and stagnant air were the main reason for the great smog of London.
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How do I make element symbols?
Answer: Each element is given its own chemical symbol, like H for hydrogen or O for oxygen. Chemical symbols are usually one or two letters long.
Explanation:Every chemical symbol starts with a capital letter, with the second letter written in lowercase. For example, Mg is the correct symbol for magnesium.
convert 4 hours into seconds (DA practice problems) must solve final answer.
1 & 2
Answer:
The answer is 14,400 seconds.
Explanation:
Hope it helps man ...
Answer:14400secondsExplanation:
When 0. 25 g of the organic compound naphthalene are burned in a bomb calorimeter, the temperature of the water in the calorimeter increases from 24. 00°C to 26. 43 °C. The calorimeter's heat capacity is 4. 13 kJ/°C. How much heat (q_{rxn}) in kilojoules is released by the combustion of the naphthalene?.
-2.5089 kJ is the amount of heat is released by the combustion of the naphthalene.
How we calculate the released heat?Released amount of heat is calculated by using the below formula:
Q = -mcΔT, where
m = mass of naphthalene = 0.25g
c = specific heat of calorimeter = 4.13 kJ/°C
ΔT = change in temperature = 26.43°C - 24°C = 2.43°C
Putting all these values in the above equation, we get
Q = - (0.25 × 4.13 × 2.43) = - 2.5089 kJ
Hence, - 2.5089 kJ heat is released.
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What features of this model will help Armando answer the question?
Answer:
The adjustable legs and the table of sand.
Note:The question is incomplete. The complete question is given below.
Using Models to Answer Questions About Systems
Armando’s class was looking at images of rivers formed by flowing water. Most of the rivers were wide and shallow, but one river was narrow and deep. Armando’s class thinks that this river is narrow and deep because:
the hill that the water flowed down was very steep, orthe sand grains that the water flowed through were very small.Armando designed the model below to try to answer the question: Why is this river so narrow and deep?
Explanation:
The model designed by Armando will be helpful to answer the question because of the following features it possesses:
1. An adjustable leg- since one of the hypotheses put forward by the class to explain why the river was narrow and deep was that the hill that the water flowed down was very steep, the adjustable legs can be lowered or raised in order to make the slope shallower or steeper so that their hypothesis can be tested.
2. A table of sand- the table of sand serves as the streambed. By adjusting the size of the sand grains to be larger or smaller, the students will be able to to test their second hypothesis that the small size sand grains that the water flowed through was the reason for the river to be narrow and deep.
The results of their experiments will enable them to come to a conclusion.
PLEASE HELP
Which of the following is a testable scientific question?
Do blue M&Ms taste better than green M&Ms?
1.What is beneath the ground on planets outside our solar system?
2.How does the age of city affect the number of trees in the city?
3.How many houses are in my neighborhood?
What does gravity do to cause rain to happen?
How does gravity affect water that is on the surface of Earth?
Answer:
When the water droplets in the cloud get too heavy they will fall. Which causes rain to fall. Gravity force pulling the droplets toward the Earth's surface.
It pulls precipitation down form could and pulls water downhill. Gravity pulls denser air and water downwards, forcing less dance air and water to move upwards.