Litmus paper and Phenolphthalein are both indicators. This means they will change colour in the presence of an acid or a base.
Litmus paper turns blue in a base and remains red when it is in contact with an acid or neutral solution. Phenolphthalein turns pink in a base, but is coluorless in an acid or neutral solution.
The characteristic bright–line spectrum of potassium is produced when electrons
A) jump to higher energy levels
B) return to lower energy levels
C) are lost by neutral potassium atoms
D) are gained by neutral potassium atoms
E) are released from the nucleus
Answer: B.
Explanation:
When the electron changes levels, it decreases energy and the atom emits photons. The photon is emitted with the electron moving from a higher energy level to a lower energy level. The energy of the photon is the exact energy that is lost by the electron moving to its lower energy level.
Hope this helps!
How many joules of heat are absorbed when 70.0 grams of water is completely vaporized at its boiling point ?
Answer: The answer would be 158,200
HURRY PLS!
A wave has a wavelength of 915 meters. what is the frequency of the light?
Answer:
327.8689 (Hz)
0.3279 (KHz)
0.0003 (MHz
0 (GHz)
which of these is an element?
KBr
O2
2KCl
FeO2
Answer:
02
Explanation:
all the other options given are compounds
Explain why the mass number of oxygen is 16
Answer:
Oxygen has an atomic number of 8 , and the mass number of an atom is the sum of its atomic number plus its neutron number. We got the mass as 16 units, and so it'll have 16−8=8 neutrons.
Explanation:
Select the molecular shape of each molecule based on the formula or Lewis structure.
Answer:
1. linear (A)
2. trigonal-planar (C)
3. tetrahedral (B)
4. linear (A)
Explanation:
Just did it on Edge 2020
The shape of a molecule can be predicted from the number of electron pairs that surround the central atom in the molecule.
The Valence Shell Electron Pair repulsion theory gives us a basis for predicting the shape of molecules. The shape of a molecule can be predicted from the number of electron pairs that surround the central atom in the molecule.
In the image shown, We can see that in HCN , carbon is the central atom and is surrounded by two atoms and no lone pairs. Since there are two electron domains around the central atom, the molecule is linear.
In the second structure, BH3 has boron as its central atom. Three electron domains surround the central atom hence the molecule is trigonal planar.
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Answer: c. ceabd
Explanation: Substances that are more dense move to the bottom of the beaker. Substances that are less dense float to the top.
use the facts that water has a higher specific heat than rock (such as Granite) to explain the differences in the temperature curves for the two cities in the graph.
Since water has a high specific heat, that results in water being able to store/require more energy in order to change it’s temperature. Since San Francisco is so close to water, that would mean that it’s temperature should vary less since water would be able to keep the temperature around the same value even if there was an increase or decrease in thermal energy.
A runner completes a 400m race in 43.9s. What is his average speed?
Answer:
average speed around 9.1 meters/second
Explanation:
400 divided by 43.9
is it true that the atomic radius of A1 is greater than the atomic radius of In ?
Answer:
Yes
Explanation:
Yes it is true
Why can two water molecules stick to each other?
PLEASE HURRY (WILL MARK BRAINLIEST)
What happens when the sound waves released by a bat hit an object?
The sound waves are diffused.
The sound waves are reflected.
The sound waves are refracted.
The sound waves are absorbed,
Answer:
B.) The sound waves are reflected.
Explanation:
On edge,
i also answered so the other person could get the brainliest
Answer:
b
Explanation:
How is heat transferred when you touch an ice cube?
Answer:
The heat is transferred from your hand to the ice, this is because, as we know, heat gets transferred from a hot object to a colder object.
In this case, our hand is clearly hotter than the ice cube.
Therefore, the heat is transferred from your hand to the ice cube.
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With circulation, the heart provides your body with:
a. oxygen
b. nutrients
C. a way to get rid of waste
d. all of the above
Explanation:
The lungs pump oxygen in and carbon dioxide out, which goes through the blood stream to help with the cell's energy needs.
Nutrients pass through the blood stream as well. The nutrients start with the digestive system (mouth, esophagus, stomach, small intestine) before going into the blood stream. The nutrients are building blocks to help make new cells when old ones die off.
When those cells die off, the body sheds them like dead skin, but internal dead cells are passed off as waste. This waste and other byproducts the body doesn't need passes through the blood stream as well.
In short, the blood stream is basically the highway to help get desired materials (eg: oxygen and nutrients) and get rid of waste (eg: carbon dioxide and other unwanted byproducts or dead cell material)
So that's why the answer includes A, B and C.
A piece of gold has a mass of 21.7 kg and a volume of 5.78 cm3 . What is the density of gold? (Convert kgg)
Answer:
The answer is 3754.33 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question
mass = 21.7 kg = 21700 g
volume = 5.78 cm³
We have
[tex]density = \frac{21700}{5.78} \\ = 3754.3252...[/tex]
We have the final answer as
3754.33 g/cm³Hope this helps you
HELP ME ASAP PLEASE IDK THIS
Answer:
cExplanation:
Which of the following happens to the particles when the temperature of liquid water drops?
Explanation:
when water is in liquid form and the temperature DROPS it becomes solid ice the process is melting , freezing and evaporation this goes in a circle
Determine the mass of 31.4 moles of Sodium.
Answer:
721.9 grams
I hope this helps!
A sample of N2H4 has a mass of 25g. Identify the numerical quantity that is needed to convert the number of grams of N2H4 to the number of moles of N2H4. (You do not need to do the actual calculation.)
Answer:
Molecular Mass
Explanation:
It's asking for the numerical quantity. That quantity would be the Molecular Mass. Take the sample mass and divide it by the molecular mass to get the number of moles.
(14g N * 2) + (1g H *4) = 32g / mol of N2H4
To get # of moles, divide the sample mass by the molecular mass
25g / 32g = 0.78125 moles
Calculate the number of moles of neon gas in 8.15 x 10^24 atoms of neon gas.
1.35 moles Ne
0.135 moles Ne
135 moles Ne
13.5 moles Ne
Answer:
13.5 moles of Ne
Explanation:
1 mole of any gas contains 6.02 x 10²³ atoms of gas
6.02 x 10²³ atoms of neon is equal to 1 mole of neon .
8.15 x 10²⁴ atoms of neon is equal to 1 x 8.15 x 10²⁴ / 6.02 x 10²³ moles
= 8.15 x 10²⁴ / 6.02 x 10²³ mole o neon
= 13.5 moles of Ne .
How many miles are there in 12327 feet
Explanation:
2.3346591 miles is in 12327 feet
Answer:
2.3346591Explanation:
Always remember, to convert
feet to miles, all you have to do is
divide the length by 5280 and then
you will get this much miles: 2.3346591
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what "waste" does the blood cell drop off at the lungs .... ANSWER ASAP AND I POINT EXTRA
Answer:
it drops off of carbon dioxide... but i believe when the blood returns to the heart it " travels" through the pulmonary veins...
use your brain :) brainliest pweasee?
Through which material does light move fastest?
Answer:
Explain that unlike sound, light waves travel fastest through a vacuum and air, and slower through other materials such as glass or water.
Explanation:
Hope this helped.
Answer:
empty space
Explanation:
Elements can be described by their properties. Some of these properties are physical properties and some are chemical properties Observe the list provided. Which one of these contains ONLY Cchemical properties
A) C,E,F
B) B,C,E
C) B, E, F
D) C,D,E
Its a c,e,f
Sadly i got it wrong
Flammability, Ability to rust and Ability to tarnish (C,E,F) are chemical properties of an element.
The property of an element is the characteristic feature of that element which helps us to differentiate it from another element.
We have
The Physical proprieties- These are features of an element which we can identify by sight and touch, Some of them include colour, hardness, boiling and ,melting point, size etcChemical properties These are the features of an element which w\e observe when the element has undergone a chemical change which changes its composition. Examples are Flammability, rust, tarnish , corrosion etc.See more here:https://brainly.com/question/2116116
HELP ME OUT PLEASE!! I NEED HELP !
This diagram represents one of the four levels of industry. Which term best
completes the diagram?
Factory employees
Oil refinery workers
Butchers
A. Quaternary sector
OB. Secondary sector
C. Tertiary sector
D. Primary sector
Answer: OB. Secondary Sectors.
Explanation: Make sure to study as the text provided, and study guide state manufacturers, butchers, and factory employees are apart of the secondary sector in the world economy. You’ll do great on Quiz 3.2.5! Make sure to study, have a g’day. Please don’t listen to people who say this answer is falsen as many other questions do, don’t be the one to spread false information as this people’s academics, here’s a picture as well ❤︎. Again, its B!
Balance the following chemical equations
Answer:
1) 3Fe + 2O(2, this is the subscript) - Fe(3)O(4)
2) 2Sr + O(2) - 2SrO
3) Sn + 2NaOH - Na(2)SnO(2) + H(2)
4) 2K + Br(2) -2KBr
5) 2C(8)H(18) + 25O(2) - 16CO(2) + 18H(2)O
In a solution, the particles of different substances are ___ a. mixed evenly, b. never mixed, c. mixed unevenly, d. separated from each other. PLEASE ANSWER ASAP TY
Identify the techniques used to separate the components of the given mixtures.
1. Faucet with cloth
2. Nails attracted by magnets
3. Pouring off liquid from rice
4. Sorting buttons with different colors
5. Use of sieve to produce finer sand
Answer: 1.valving , 2. picking, 3. decantation , 4. sorting, 5. seiveing
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A car with a mass of 800 kg is accelerated with a force of 6000 N. If resisting forces are ignored, what is the acceleration of the car? yen
Answer:
The answer is 7.5 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
f is the force
m is the mass
From the question we have
[tex]a = \frac{6000}{800} = \frac{60}{8} = \frac{15}{2} \\ [/tex]
We have the final answer as
7.5 m/s²Hope this helps you
1. The human eye can detect wavelengths of light as short as 0.000037 cm. What is this
wavelength in nanometers?
Answer:
0.000037 cm is 370 nanometers
Explanation: