Answer:
7.2 meters per hour
Explanation:
It is given that,
The speed of a paramecium is 2,000 micrometers per second.
We need to find the speed of the paramecium in meters per hour.
We know that,
[tex]1\ \mu m=10^{-6}\ m[/tex]
and
1 hour = 3600 seconds
[tex]v=2000\ \dfrac{\mu m}{s}\\\\=2000\times \dfrac{10^{-6}\ m}{(\dfrac{1}{3600})\ s}\\\\=7.2\ \text{meters/hour}[/tex]
Hence, the speed of the paramecium is 7.2 meters per hour.
Which statement about the physical change of liquid water boiling into steam is true?
The heat added represents an energy change.
The action cannot be reversed.
The steam cannot conserve mass.
The weight lost represents a mass change.
Answer:
it A
Explanation:
ed 2020
Students learned that objects can exert forces on other objects without touching. Which three investigations will provide evidence what they have learned. a measuring how close a soda can must be before it rolls toward a balloon that has been rubbed
Answer:
b
Explanation:
Cats are aliens, sent to spy on us. Is this statement about cats a scientific theory? Explain your answer, including whether you can provide evidence to support the statement.
Answer:
No, it's not a scientific theory because it has no merit or evidence to support that claim.
Explanation:
When salt is placed on ice the ice melts. explain why?
Explanation:
When salt is added to ice, salt first dissolves in the film of liquid water that is always present on the surface, thereby lowering the ice's freezing point
please mark as brainliest ,I really need it
The loops in Ptolemy’s model, and those shown on the video, are called motion. This phenomenon is caused by Earth’s orbit than those of other planets.
Answer:
The loops in Ptolemy’s ✔ geocentric model, and those shown on the video, are called
✔ retrograde motion. This phenomenon is caused by Earth’s
✔ faster orbit than those of other planets.
Explanation:
Answer:
✔ geocentric
✔ retrograde
✔ faster
Explanation:
What do the elements Nickel and Technetium have in common?
Answer:
Both Nickel (Ni, 28, 58.69) and Technetium (Tc, 43, [98]) have these features in common:
transition metalssome gray color (Tc is silver)are in the d blockhave two electrons in valence shell (although Tc's valence is 6)very similar electronegativity levels (1.9 vs 1.91)don't have a refractive indexdon't have a critical temperaturedon't have a heat of combustion measurementdon't have an EU Number or NFPA hazard leveldon't have an autoignition point or a flashpointThere are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Therefore, nickel (Ni) and technetium (Tc) belongs to d block element.
What is periodic table?Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.
Periodic table help a scientist to know what are the different types of elements are present in periodic table so that they can discover the new elements that are not being discovered yet.
Both Nickel (Ni) and Technetium (Tc) have these features in common:
Both are transition metals that is belong to d block
Both have two electrons in valence shell
Electronegativity value of these elements are same
Therefore, nickel (Ni) and technetium (Tc) belongs to d block element.
Learn more about periodic table, here:
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What is density????????????????
Answer:
Density is the mass per unit volume
Explanation:
Density is defined as mass divided by volume: where "p" is the density, "m" is the mass, and "V" is the volume.
Potassium, K, had 19 protons, 20 protons, 19 electrons. What is the charge of the atom’s nucleus.
HELP
Answer:
+ 19
Explanation:
The following data were obtained from the question:
Proton = 19
Neutron = 20
Electron = 19
Charge on nucleus =.?
From a background understanding of the structure of an atom, the nucleus of an atom contains protons and neutrons with the proton being positively charged and the neutron is neutral while the electrons being negatively charged revolve around the nucleus.
From the above question, we understood that the potassium atom has 19 protons which are all positively charged. This simply means that the nucleus has a charge of + 19 since the neutrons are neutral.
which of the following elements is the largest?
A. Boron
B. Nitrogen
C. Oxygen
D. Carbon
Answer:
A) Boron
Explanation:
I put oxygen and it was wrong lol. So, it said it was Boron
Which factor causes a decrease in the rate of dissolution?
decreasing the amount of solute
increasing the stirring of the solution
decreasing the surface area of the solute
increasing the temperature of the solvent
Answer:
The correct option of the first option
Explanation:
Dissolution of a solute in a solution is the process in which the solute interacts with the solvent leading to the disappearance of the solute to form a solution. Rate of dissolution is primarily affected by three factors namely
Stirring of the solution: Stirring the solution causes the solute to interact more with the solvent, thus increasing the rate of dissolution.
Surface area of the solute: The smaller the surface area of the solute, the more easier it is for it (the solute) to interact with the solvent. Hence, the smaller the surface area, the faster the rate of dissolution.
Temperature of the solvent: An increase in temperature of the solvent causes the generally causes more things to dissolve in this solvent due to increased energy of molecules in the solvent, which causes the molecules of the solute and solvent to interact more.
A decrease in the amount of solute will reduce the amount of interaction the solute (since it is in lesser quantity) have with the solvent hence the rate of dissolution will also be low (even though a solution will still be formed).
There are different factors that influences chemical equations. The factor that causes a decrease in the rate of dissolution is decreasing the surface area of the solute.
Dissolution rate is simply known as the transfer rate of some specific drug molecules from the solid particles which is usually crystalline in nature into solution as self free drug molecules. The rate of Dissolution can be determined by the forces of the crystal.Surface area is known to affect the rate of dissolution. Note that When the total surface area of the solute particles is increased, the solute will then dissolves more quickly than ever.
The breaking of a solute into smaller pieces in turn do increases its surface area and increases its rate of solution and the act of stirring, do allows the solute to dissolve faster.
Learn more about Dissolution from
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Who first arranged the elements according to atomic mass ?
Answer:
Dmitri Mendeleev
Explanation:
In 1869, just five years after John Newlands put forward his Law of Octaves, a Russian chemist called Dmitri Mendeleev published a periodic table. Mendeleev also arranged the elements known at the time in order of relative atomic mass, but he did some other things that made his table much more successful.
All elements on the periodic table are________
Answer:
Explanation:
arranged in order of increasing.
Chelsea went ice skating. The ice, her skates, the Zamboni, and the rink building were all examples of solids she encountered. She developed a model of the particles in the ice. Which of statements about the particles present in her model of solid are true?????? Choose the statements that apply.
A. they vibrate in place
B. they slide past each other
C. they are packed very closely together
D.they cause the solid to have a definite volume and definite shape
I think it is d c and a I may be wrong☺️
Answer:
Answers are C, D
Explanation:
Solid particles always stick together no matter what happens unless it is changing into a liquid. If you are talking about vibration for solid particles that only applies to thermal vibratio so not A. They do not slide past each other because they are packed very tightly together. They have a definite shape and volume because they stay together unless facing heat. Hopefully this helps you :)
pls mark brainlest ;)
The statements about the particles present in her model that are true;
C and D
They are packed very closely together ( C ) They cause the solid to have a definite volume and definite shape ( D )Particles of solids are closely packed and this feature distinguishes a solid from other forms of matter ( liquid and gas ). Solids have a definite volume and shape due to their closely packed particles.
Vibration in solids occur when solids are under thermal pressure and from her skating activity, there was no form of thermal pressure therefore solids vibrating in place would not be included in her model.
Hence we can conclude that The statements about the particles present in her model that are true; they are packed very closely together and They cause the solid to have a definite volume and definite shape
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Click here to access the interactive simulation. You will practice balancing chemical equations by playing an interactive game. After accessing the website, select the game box and start with level 1, followed by levels 2 and 3. The goal of these games is to have the same number of atoms on each side of the equation.
In level 1, you balanced the equation N2 + H2 →
NH3. What number did you place in front of ammonia (NH3)?
In level 2, you balanced the equation C + H2O → CH4 +
CO2. What number did you place in front of carbon dioxide (CO2)?
In level 3, you balanced the equation NH3 + O2 → NO2 +
H2O. What number did you place in front of water?
Answer:
In level 1, you balanced the equation N2 + H2 →
✔ 2
NH3. What number did you place in front of ammonia (NH3)?
In level 2, you balanced the equation C + H2O → CH4 +
✔ 1
CO2. What number did you place in front of carbon dioxide (CO2)?
In level 3, you balanced the equation NH3 + O2 → NO2 +
✔ 6
H2O. What number did you place in front of water?
Explanation:
Edge:2020
Answer: 2,1,&6
Explanation: the answer
- Write down Rutherford's atomic model with diagram .also write down defects of Rutherford's atomic model. - write down neil bohar atomic model
this is the answer
sorry if the answer is wrong
Which ion has a charge of 2-?
Ion A: 8 Protons,10 Neutrons,10 Electrons
Ion E:9 Protons,10 Neutrons,10 Electrons
Ion G:11 Protons,12 Neutrons,10 Electrons
Ion J:12 Protons,12 Neutrons,10 Electrobs
Answer:
A
Explanation:
More electrons than protons, thus giving the atom an overall charge of -2
_____________ dating places the rocks and rock layers in an area into sequential order. ________ dating gives an exact date on rock layers.
Geologic, Absolute
Relative, Geologic
Relative, Absolute
Time, Geologic
What role does science play in changes?
Answer:
Science, as well as technological and metaphysical questions, should offer solutions to our everyday problems. The consistency of responses offered to society should be increased by research. Science, however, still needs to interact with society in conversation.
Explanation:
A student measures the mass of a substance as 1.7132kg and it's volume as 0.65l. What is the density substance in g/mL? Round your answer to the correct number of significant figures
Answer:
The substance has a density of 2.636 grams per mililiter.
Explanation:
We must remember that density ([tex]\rho[/tex]), measured in grams per mililiters, is the mass of the substance ([tex]m[/tex]), measured in grams, divided by its volume ([tex]V[/tex]), measured in mililiters. That is:
[tex]\rho = \frac{m}{V}[/tex]
In addition, a kilogram equals 1000 grams and a liter equals 1000 mililiters. If we know that [tex]m = 1713.2\,g[/tex] and [tex]V = 650\,mL[/tex], then:
[tex]\rho = \frac{1713.2\,g}{650\,mL}[/tex]
[tex]\rho = 2.636\,\frac{g}{mL}[/tex]
The substance has a density of 2.636 grams per mililiter.
Discuss the sources and harmful effects of the following air pollutants.(i) Carbon monoxide (ii) Sulphur dioxide (iii) Oxides of nitrogen
Answer:
Oxides of Nitrogen (NOx)
NOx is a collective term used to refer to two species of oxides of nitrogen: nitric oxide (NO) and nitrogen dioxide (NO2).
Annual mean concentrations of NO2 in urban areas are generally in the range 10-45 ppb (20-90 µgm-3). Levels vary significantly throughout the day, with peaks generally occurring twice daily as a consequence of "rush hour" traffic. Maximum daily and one hourly means can be as high as 200 ppb (400 µgm-3) and 600 ppb (1200 µgm-3) respectively.
Globally, quantities of nitrogen oxides produced naturally (by bacterial and volcanic action and lightning) far outweigh anthropogenic (man-made) emissions. Anthropogenic emissions are mainly due to fossil fuel combustion from both stationary sources, i.e. power generation (21%), and mobile sources, i.e. transport (44%). Other atmospheric contributions come from non-combustion processes, for example nitric acid manufacture, welding processes and the use of explosives.
Sulphur Dioxide (SO2)
SO2 is a colourless gas. It reacts on the surface of a variety of airborne solid particles, is soluble in water and can be oxidised within airborne water droplets.
Annual mean concentrations in most major UK cities are now well below 35 ppb (100 µgm-3) with typical mean values in the range of 5-20 ppb (15-50 µgm-3). Hourly peak values can be 400-750 ppb (1000-2000 µgm-3) on infrequent occasions. Natural background levels are about 2 ppb (5 µgm-3).
The most important sources of SO2 are fossil fuel combustion, smelting, manufacture of sulphuric acid, conversion of wood pulp to paper, incineration of refuse and production of elemental sulphur. Coal burning is the single largest man-made source of SO2 accounting for about 50% of annual global emissions, with oil burning accounting for a further 25-30%.
Carbon Monoxide (CO)
Carbon Monoxide is a colourless, odourless, tasteless gas that is slightly lighter than air.
Natural background levels of CO fall in the range of 10-200 ppb. Levels in urban areas are highly variable, depending upon weather conditions and traffic density. 8-hour mean values are generally less than 10 ppm (12 mgm-3) but have been known to be as high as 500 ppm (600 mgm-3).
CO is an intermediate product through which all carbon species must pass when combusted in oxygen (O2). In the presence of an adequate supply of O2 most CO produced during combustion is immediately oxidised to carbon dioxide (CO2). However, this is not the case in spark ignition engines, especially under idling and deceleration conditions. Thus, the major source of atmospheric CO is the spark ignition combustion engine. Smaller contributions come from processes involving the combustion of organic matter, for example in power stations and waste incineration.
Ozone (O3)
O3 is the tri-atomic form of molecular oxygen. It is a strong oxidising agent, and hence highly reactive.
Background levels of O3 in Europe are usually less than 15 ppb but can be as 100 ppb during summer time photochemical smog episodes. In the UK ozone occurs in higher concentrations during summer than winter, in the south rather than the north and in rural rather than urban areas.
Most O3 in the troposphere (lower atmosphere) is formed indirectly by the action of sunlight on nitrogen dioxide - there are no direct emissions of O3 to the atmosphere. About 10 - 15% of tropospheric O3 is transported from the stratosphere where it is formed by the action of ultraviolet (UV) radiation on O2. In addition to O3, photochemical reactions involving sunlight produce a number of oxidants including peroxyacetyl nitrate (PAN), nitric acid and hydrogen peroxide, as well as secondary aldehydes, formic acid, fine particulates and an array of short lived radicals. As a result of the various reactions that take place, O3 tends to build up downwind of urban centres where most of NOx is emitted from vehicles.
Explanation:
Explain how NOTHING is ZERO, but ZERO is more than NOTHING?
Answer:
Nothing can be zero, but zero isn't nothing. If someone asks you if you have money and you say "I've got nothing!" when you actually don't have a cent, then you have zero money. However, zero is a number, so it itself is something, therefore more than nothing. So technically, you do have something.
When zero is on a number line, you could classify it as nothing, but it is the number between 1 and -1. Hypothetically speaking, if you took the zero away, wouldn't the number line be the same?
Zero isn't positive or negative. The number zero on a graph, or in a coordinate can tell you where something is. Zero can be a word to describe if something is existent, or non-existent.
Okay, my brain hurts.
How do you know if a energy level is full
Answer:
By checking Level.ok!!
HELPPPP!
can we manufacture water? why or why not
Answer:
No because water needs to have no salt
Explanation:
Find the volume of the a with a length of 5cm, a width of 5cm, and height of 10cm.
Answer:
250 cm³
Explanation:
V = l × w × h
V = (5) × (5) × (10)
V = 250 cm³
All atoms that react
Answer: Electrons
Explanation:
What is a particle with one positive charge called?
Answer:
Proton: A positively charged particle found in the nucleus of an atom. A proton contributes one atomic mass unit to the total atomic weight of an atom.
Explanation:
Answer:
A proton
Explanation:
A proton is a positive charge found in an atom
The total number of d orbitals in the third principal energy
level is
Answer:
Five.
Explanation:
The third principal energy level has one s orbital, three p orbitals, and five d orbitals, which can each hold up to 10 electrons. This allows for a maximum of 18 electrons.
What is the mass of 42.0 mL of a liquid with a density of 1.65 g/mL?
Answer:
The answer is
69.30 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
volume = 42 mL
density = 1.65 g/mL
The mass is
mass = 1.65 × 42
We have the final answer as
69.3 gHope this helps you
What should you always do at the end of a lab
Answer:clean up the area
Explanation:
Which of the following is one way creativity can help scientists?
Answer:
One way creativity is helpful to scientists is when they need to come up with a experiment or cure for something their imaginastion is very helpful. The reason for that is with creativity they could get answers much quicker!
Explanation:
Answer:
I agree with that answer