Answer:
Cork the test tube and then heat it gently near the bottom only.
Explanation:
If the contents of the test tube is flammable, then it can catch fire easily at any time. In that case, we can not heat the mixture in an open test tube, that will make the flammable substance to catch fire easily.
In heating such a flammable material, the test tube should be securely corked and heat is delivered gently to the bottom of the tube. This will prevent the substance from bursting into flames spontaneously.
A mineral is described as "metallic." This description refers to its:
Answer: properties
Explanation:
The element which has the properties
Mallablity
Ductility
Lusterous
High electric. Conductivity
High tensile strength is said to be metal.
why does spoiled food produce foul smell
Answer:
There is spoilage microbes growing on the food, such as bacteria, yeasts, and mold. The odor can either come from the chemicals that are released from the food as the microbes decompose it down, or the chemicals are produced by the microbes themselves.
Answer:
When food goes bad and starts to become pungent, it is most often due to the growth of spoilage microbes such as bacteria, yeasts and mold. Odors can come from two sources: chemicals that are released from the food as the microbes decompose it, or chemicals produced directly by the microbes themselves.
Hope this answer correct :)
how many orbitals are in the first energy level? A. 3 B.4 C.2 D.1
Answer:
One orbital
Explanation:
There is only one orbital in the first energy level of any atom of an element.
What is energy level?Electrons present in an atom revolve in different orbits which are stationary states and are also called as energy levels. The energy levels are numbered as integers which are also called as principal quantum numbers.
Energy of the stationary state is given as E= -R
1/n² where R
is the Rydberg's constant. When an electron is excited, and it moves from lower to higher energy levels there is absorption of energy, while when it moves from higher energy level to lower energy level it radiates or gives out energy in the form of radiation.
They can also be defined as the distances between electron and nucleus of an atom . Electrons present in K energy level have least energy .Energy level diagrams are studied to understand nature of bonding , placement of electrons in orbits and and elemental behavior under certain conditions.
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PLEASE HELP ME ON HERE HAVING TROUBLE!!!!
What errors tend to lead to pseudoscience?
Answer:
Some errors includes:
- Having contradictory information
- Exaggerated and false cliams
- Reliance on bias rather than facts
- etc
Explanation:
Pseudoscience is a non-science that falsely portrays itself as real science. It does so by copying parts of real science or ignoring sections of the scientific method within an investigation. Even a tiny mistake can turn a scientific explanation into a pseudoscientific claim.
For example, if a group of scientists want to know if students prefer the taste of a particular type of soda, they must control all factors in their experiment except for the students' sense of taste. If they conduct their tests on students and allow them to see the color of the soda they are testing, then their results are unreliable. There is bias in their results. They would not be able to claim any preference for one soda or another because students may have picked a soda based on its color, not its taste.
Convert 1.25 kg into grams
Since we are going from a larger unit to a smaller unit, we multiply.
So we multiply 1.25 by the conversion factor, which is 1,000.
This gives us 1,250 grams
Question 5(Multiple Choice Worth 3 points)
(01.04 LC)
Complete this sentence. The electrical conductivity of a sample will
when the size of the sample increases.
O decrease
O stay the same
O increase
O be unable to be determined
Answer: B. Stay the same
A block of wood has a mass of 180 grams it is 10.0cm long, 6.0cm wide and 4.0cm thick what is it’s volume and density
Answer:
Density = 0.75 g/cm³Explanation:
Density of a substance is given by
[tex]Density(\rho) = \frac{mass}{volume} [/tex]From the question
mass of the wood = 180 g
Since the wood is a cuboid we can find the volume using the formula
Volume = length × width × height
From the question
length = 10cm
width = 6 cm
height = 4 cm
Volume = 10 × 6 × 4 = 240 cm³
Substitute the values into the above formula and solve for the Density
That's
[tex]Density(\rho) = \frac{180}{240} \\ = \frac{3}{4} [/tex]We have the final answer as
Density = 0.75 g/cm³Hope this helps you
basic atomic structure of argon
Answer:
structure of argon
Explanation:
The nucleus contains 18 protons ( red) and 22 neutrons (orange). 18 electrons (white) occupy shells ring.
Which of these steps would most likely be part of a lab procedure?
Write a hypothesis to answer a question.
Write a title at the top of a completed lab report.
Record the time to complete a chemical reaction.
Create a question on the cause of a chemical reaction.
Answer:
the answer is C
Explanation:
Record the time to complete a chemical reaction
The step that will be part of a lab procedure is; "Record the time to complete a chemical reaction."
A lab procedure refers to something that is done in the laboratory as part of an experiment.
If we look at the options carefully, we will notice that the only thing that is part of a laboratory experiment is "Record the time to complete a chemical reaction."
This action can be carried out in a live lab procedure.
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7 When carbon is heated in a limited supply
of oxygen, a gas is obtained
(a)What is the name of this gas?
Write an equation for this reaction
IdState two physical properties of the gas
State niso uses of the gas
je)The gas is said to be poisonous. Why?
8(a) Using diagrams and equations, describes
how you would prepare samples of carbon
(ID oxide from - (1) Carbon (IV) oxide and
other reagents () Ethanedioic acid and
other reagents
Answer:
please mark my answer brainliest
Explanation:
its carbon monoxide
.....
Answer:co
Explanation:the compounds is carbon monoxide and it is found in fired coal it is poison for a human and it may cause death .
Can youmark my answers the brainliest.
Can someone help me with this please....
a. vinegar
b. Mineral deficiencies in the body can make joint pain worse. Because Vinegar contains the calcium, magnesium, potassium, and phosphorus your body needs, it helps as a supplement and therefore reduces pain.
1. in making fertilisers which are chemical compounds or salts to increase fertility of soil.
2. lithium hydroxide is used in space because of its high absorption of carbon dioxide and the small amount of heat produce by the reaction.
3. Acid rain has a lower pH than "normal" rain . Rain is naturally somewhat acidic with a pH between 5.0-5.5 typically. Acid rain has a pH that is below this: 4.4-4.2
4. lemon juice is an anti bacterial and a good germicidal solution which helps in removing the unseen bacteria on our hands.
Hope this helps :)Bob walks 81m East and then he walks 103m East.
Answer:
81m + 103 m
= 184 m to the east
can someone help me on this please ?
in which atom is the number of protons equal to the number of neutrons?
Answer:
neutral
Explanation:
What is the volume in milliliters, of a sample of helium that has a mass of 1.73 x 10^-3g given that the density is 0.178 47g/L
Given :
Mass of helium sample , [tex]m=1.73\times 10^{-3}\ g[/tex] .
Density of helium , [tex]\rho=0.178\times 10^{-3} \ g/cm^3[/tex] .
To Find :
The volume in millilitres .
Solution :
Density is given by , [tex]\rho=\dfrac{m}{V}[/tex]
So , volume is , [tex]V=\dfrac{m}{\rho}[/tex]
Putting given values in above equation we get :
[tex]V=\dfrac{1.73\times 10^{-3}}{0.178\times 10^{-3}}\ ml\\\\V=9.72\ ml[/tex]
Therefore , volume of sample of helium is 9.72 ml .
Hence , this is the required solution .
The volume of sample in milliliters is 9.72 mL .
Given data:
The mass of sample is, [tex]m=1.73 \times 10^{-3} \;\rm g[/tex].
The density of the helium sample is, [tex]\rho = 0.17847 \;\rm g/L =0.17847 \times 10^{-3} \;\rm g/cm^{3}[/tex].
The given problem is based on the concept of density. The density of any substance is equal to the mass per unit volume of the substance. The expression is given as,
[tex]\rho =\dfrac{m}{V}\\\\\\V =\dfrac{m}{\rho}\\\\\\V =\dfrac{1.73 \times 10^{-3}}{0.17847 \times 10^{-3}}\\\\V =9.72 \;\rm mL[/tex]
Thus, we can conclude that the volume of sample in milliliters is 9.72 mL .
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how are sound waves different from the waves in the sea or the ripples on water???
Answer:
water wave shake energy over the surface to the sea, while sound waves thump energy trough the body of the air. sound waves are compression waves
Hope this helps :)
how many electrons does the predictable (most common) ion of flourine contain
Answer:
8
Explanation:
This is because fluorine has the 9 electrons but because it's an ion it gives out an electron thereby losing an electron...so the electron number is 8
Answer:
8electron
Explanation:
Fluorine has 9electron on its orbit although it loses one weak electron to another strong element during ionization. example: Cl-F
Write a simple procedure for measuring out 2.6 grams of sodium bicarbonate NaHCO3 or commonly known as baking soda?
PLEASE I REALLY NEED THIS!!! :/
Answer:
See explanation
Explanation:
If I intend to measure 2.6 g of sodium bicarbonate, I need a spatula, a filter paper, and a weighing balance.
The filter paper is placed on the balance and the balance is adjusted to read zero. The spatula is now used to collect the sodium bicarbonate solid from its container and gradually drop it on the filter paper while watching the mass read out by the balance. This continues until the balance reads 2.6g.
What is a scientific theory? (2 points)
a
A law that is always true
A hypothesis about nature
C с
An educated guelmes based on observations
d
An explanation of how the natural world works
Answer:A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world.
Should be right
A scientific theory is defined to be the part and explanation of the natural world, its phenomena, and the detailed description of the working. Thus, option D is correct.
What is the relation between scientific theory and hypothesis?
A scientific theory is said to be the well-accepted and well-proposed explanation of the topic matter that has repeatedly undergone experiments to prove its ingenuity and uses well-constructed facts and hypotheses.
The hypothesis is the basis of the scientific theory as it gives the idea about the subject issue for which the experimental design is set for the analysis and reach a conclusion.
The scientific theory is proposed based on a hypothesis that assumes something based on limited evidence that is evaluated and undergoes experiments for it to be proved true or false.
Therefore, option D. a scientific theory is the explanation of the working of the natural world.
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In each pair of statements, choose the example that is more reliable.
Statement 1
The company Herbal Remedies Inc.
announced today that its antiobesity skin
treatment is safe and effective.
Statement 2
The US Food and Drug Administration (FDA)
announced today that cancer treatment X,
manufactured by Pharma Inc., is safe and
effective.
Statement 1
An independent chemical analysis paid for by
local residents determined that wells are
contaminated with dioxin at a concentration
of 3 ppb.
Statement 2
The chemical company Chemicals Inc. insists
that local groundwater has not been affected
adversely by a leak in its waste handling
system.
Answer:
"statement 2" for the first pair and "statement 1" for the second pair
Explanation:
A cylinder rod formed from silicon is 46.0 cm long it has a mass of 3.00 kg. The density of silicon is 2.33 g centimeters cubed. What is the diameter of the cylinder?
Answer:
Explanation:
First find the volume from the density.
d = mass/volume
mass = 3.00 kg = 3000 grams
density = 2.33 g/cm^3
volume = mass/ density
volume = 3000 / 2.33
volume = 1287.6 cm^3
============================
Next use the volume to find the radius.
V = pi * r^2 * h
V = 3.14 * r^2 * 46
1287.6 /46 = 27.99
27.99 / 3.14 = 8.91
r^2 = 8.91
r = 2.99
2r = d = 5.97
A cake recipe calls for 0.75 cups of milk, but all you have is a tool that measures out one tablespoon. How many tablespoons of milk needs to be put in the cake batter? Hint: 16 tablespoons = 1 cup
Answer:
12 tablespoons
Explanation:
because 3/4 of 16 tablespoons is 12 tablespoons
16x 0.75 =12
Determine the volume in cm3 of 7.2 x 10-4 m3 ?
Answer:
The volume of [tex]7.2\times 10^{-4}\ m^3[/tex] is equal to 720 cm³.
Explanation:
We know that,
1 m = 100 cm
We need to convert [tex]7.2\times 10^{-4}\ m^3[/tex] to cm³.
Also,
1 m³ = 10⁶ cm³
To convert [tex]7.2\times 10^{-4}\ m^3[/tex] to cm³, the step is as follows :
[tex]7.2\times 10^{-4}\ m^3=(7.2\times 10^{-4}\times 10^6 )cm^3\\\\=720\ cm^3[/tex]
So, [tex]7.2\times 10^{-4}\ m^3[/tex] is equal to 720 cm³.
Chromatography separates a solution based on differences in how its components _____ in different phases of matter.
Answer:
Affinities
Explanation:
Chromatography is a laboratory technique used for separation of mixture.
In chromatography, the separation is based on different affinities of components in different phases of matter (mobile phase and stationary phase). Different chemical species have different affinities that is the electronic property of the chemical species and form bond with stationary phase.
Hence, the correct option is "Affinities".
What is the main hitch or problem in getting fusion to occur?
Answer:
working with intense pressure and heat
Explanation: you would you have to work with intense pressure and heat in order to fuse two hydrogen nuclei together to create helium isotopes.
Answer:
The main problem is achieving ignition to start the reactions. Fusion reactions can occur only at extremely high temperatures.
Explanation:
Questions
1.
What is diffusion?
2
Explain the process of osmosis with the help of examples.
3.
Define the term 'active transport'.
State the difference between active transport and diffusion.
Answer:
Explanation:
1. diffusion is a physical process when there is random motion of molecules by which there is a net flow of matter from a region of high concentration to a region of low concentration.
2. Osmosis is the diffusion of water where molecules of water move passively (without energy) from high concentration to low concentration. eg: the way water rushes into a sponge.
3. Active transport moves particles from low to higher concentration. The difference between diffusion and active transport is diffusion does not require energy (eg: oxygen moving from the airways to the lungs - there is very little oxygen in the lungs but lots in the air). whereas active transport does require energy (eg: when plants take up nutrients from the soil. The soil does not have a large concentration of nutrients, but the plant does)
Which of the following MOST directly influences a measurable outcome in an experiment? a. An independent variable b. A variable hypothesis c. A dependent variable d. Previous information
Answer:
A). An independent variable
Explanation:
The Independent variable is characterized itself as the variable that is controlled or manipulated by the experimenter to observe its direct impact on the dependent variable. It is a variable that is not dependent and can stand alone. For example, if a student aims to observe the impact of temperature on solubility of a substance(sugar/salt) in a liquid, the temperature will be the independent variable as any change in the temperature will directly affect the solubility power of the liquid. Thus, option A is the correct answer.
Answer:
D.
Explanation:
Amylose is _____ chain of _________ units connected by _________ bonds. Cellulose is _________ chain of _________ units connected by _________ bonds.
a. e | D-fructose |
b. L-glucose |
c. B-1,6-glycosidic |
c. a-1,4-glycosidic |
d. a-1.6-glycosidic |
e. B-1,4-glycosidic |
f.a branched |
g. an unbrached |
h. L-fructose
Answer:
The options to the question is incomplete, it should contain
D-glucose
1. Amylose- Unbranched, D-glucose, a-1,4-glycosidic
2. Cellulose- Unbranched, D-glucose, B-1,4-glycosidic
Explanation:
Amylose is one of the two polymeric components of starch, the other being amylopectin. Amylose is a polymer, made up of glucose monomers. In the structure of amylose, it is a linear (unbranched) chain of D-glucose subunits connected by α-1,4-glycosidic bonds.
On the other hand, cellulose is another polymer of glucose that makes up the cell wall of plant cells, conferring rigidity on it. It is a complex carbohydrate made up of many glucose units. Cellulose is an unbranched (linear) chain of D-glucose units connected by B-1,4-glycosidic bonds.
Answer: The options are incomplete .
The correct one is D-glucose .
A. Amlyose is Unbranched, D-glucose,
connected by -1,4-glycosidic bond.
2. Cellulose is Unbranched chain D-glucose, connected by B-1,4-glycosidic bond
Explanation:
AMYLOSE is a polysaccharide that is made up of D glucose units which is connected by alpa 1, 4 glycosidic bond. It has a tight helical structure. It is a resistant starch that is not easily digested . It is an important animal digestive storage.
Cellulose is a polysaccharide also made up of D glucose and connected by beta 1,4 glycosidic bonds. cellulose . It is the major composition of plant cell walls. It give rigidity and strength to the cell wall.
List the four states of matter, from top to bottom, in order of decreasing energy.
They are. solids liquids gases and plasma. and fift one in man made.
24. What volume of a 0.0200M calcium hydroxide is required to neutralize 35.00 mL of 0.0500M nitric acid
Answer:
THE VOLUME OF 0.200M CALCIUM HYDROXIDE NEEDED TO NEUTRALIZE 35 mL of 0.050 M NITRIC ACID IS 43.75 mL.
Explanation:
Using
Ca VA / Cb Vb = Na / Nb
Ca = 0.0500 M
Va = 35 mL
Cb = 0.0200 M
Vb = unknown
Na = 2
Nb = 1
Equation for the reaction:
Ca(OH)2 + 2HNO3 --------> Ca(NO3)2 + 2H2O
So therefore, we make Vb the subject of the equation and solve for it
Vb = Ca Va Nb / Cb Na
Vb = 0.0500 * 35 * 1 / 0.0200 * 2
Vb = 1.75 / 0.04
Vb = 43.75 mL
The volume of 0.02M calcium hydroxide required to neutralize 35 mL of 0.05 M nitric acid is 43.75 mL
The volume of 0.0200 M calcium hydroxide that would be required to neutralize 35.00 mL of 0.0500 M nitric acid will be 43.75 mL
From the equation of the reaction:
[tex]Ca(OH)_2 + 2 HNO_3 ---> Ca(NO_3)_2 + 2 H_2O[/tex]
The mole ratio of calcium hydroxide to nitric acid is 1:2.
Mole of nitric acid = molarity x volume
= 0.0500 x 35.00/1000
= 0.00175
Thus, the mole of the calcium hydroxide can be calculated as:
0.00175/2 = 0.000875
Volume of calcium hydroxide = mole/molarity
= 0.000875/0.0200
= 0.04375 L
= 43.75 mL
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