answer:
the reason is to ensure more solute is dissolving as it cools down. it is important to do it slowly because water will be sucked into buchner flask by a partial vaccum through the rubber tubing and be able to arrange molecules.
What type of reaction is represented by the chemical equation shown
below?
2PbO2 → 2PbO + O2
decomposition
single replacement
synthesis
deouble replacement
Answer:
Decomposition reaction
Explanation:
2PbO2 → 2PbO + O2
2PbO2 is reactant.
2PbO + O2 is the product.
Definition : -
Decomposition reaction is a chemical reaction in which a single reactant breaks down to simpler products.
Please answer quickly
how to scientists know where to put electrons in the atom
a. probability
b. ratio and proportions
c. algebra
d. geometry
Answer:
a).
Explanation:
precise electron locations cannot be calculated, only predicted based on previous calculations. they cannot know whether or not an electron will be or will not be somewhere specific
have a nice day!
What is true of a saturated solution?
Answer:
A saturated solution is a solution that contains the maximum amount of solute that is capable of being dissolved. At 20°C, the maximum amount of NaCl that will dissolve in 100. g of water is 36.0 g. If any more NaCl is added past that point, it will not dissolve because the solution is saturated.
If you weigh 60 pounds on Earth, your weight is _______on the moon (the moon has 1/6 the gravity of Earth).
Answer:
10 pounds
Explanation:
If the moon has 1/6 the gravity of earth, divide your weight on earth by 6 to find your weight on the moon
60 / 6 = 10 pounds
When does an electrically charged object attract another object?
A. When one object is far away from the other
B. When each object is negatively charged
C. When the objects are oppositely charged
D. When each object is positively charged
Answer:
C. When the objects are oppositely charged
Explanation:
Electrostatic interactions are commonly observed whenever one or more objects are electrically charged. Two oppositely-charged objects will attract each other. A charged and a neutral object will also attract each other. And two like-charged objects will repel one another.
From Bing, this is not my work
Answer:C
Explanation:
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC! lol i think its c
Compare and contrast how light acts as a wave and as a particle
here you go
Explanation:
the flow of photons is a wave. ... The various properties of light, which is a type of electromagnetic wave, are due to the behavior of extremely small particles called photons that are invisible to the naked eye
what is the characteristics of crystals
CHEMMMMMMMMM HELPPPPPP PLEASEEEE
Answer:
: \large \boldsymbol {\rm x > 5 \ or \ x\in (5\ ; \ \infty ) }x>5 or x∈(5 ; ∞)
Step-by-step explanation:
\begin{gathered}\large \boldsymbol {} \displaystyle -2(3x+2) > -8x+6 \\\\ -6x-4 > -8x+6 \\\\ 8x-6x=6+4 \\\\ 2x > 10 \\\\ x > 5 \ or \ x\in (5\ ; \ \infty )\end{gathered}
−2(3x+2)>−8x+6
−6x−4>−8x+6
8x−6x=6+4
2x>10
x>5 or x∈(5 ; ∞)
What are the three zones in almost all human cells?
O cytoplasm, mitochondria, plasma membrane
O ribosomes, genetic material, cytoplasm
O nucleus, cytoplasm, plasma membrane
O mitochondria, genetic material, plasma membrane
What are the ways that heat transfers? identify common examples of heat transfer.
Answer:
Conduction is the process of heat being transferred between objects through direct contact, and it's the most common type of heat transfer. For example, in cooking the burners on stoves will conduct heat energy to the bottom of a pan sitting on top of it. From there, the pan conducts heat to its contents.
Explanation:
Why do you think the term ionic is used to describe compounds formed from a metal element and a nonmetal element?
Answer:
All compounds form when atoms of different elements share or transfer electrons. Compounds in which electrons are transferred from one atom to another are called ionic compounds.
Explanation:
Because the positive and negative charges cancel out, an ionic compound is neutral in charge.
Which statement best describes a physical change?
1 Changes can occur to certain chemical properties of the substance, but the overall shape of the substance will remain the same.
2 Changes can occur to certain physical properties of the substance, but the overall shape of the substance will remain the same.
3 Changes can occur to physical properties of a substance, but the chemical composition of the substance remains the same.
4 Changes can occur to chemical properties of a substance, but the chemical composition of the substance remains the same.
Answer: 3 Changes can occur to physical properties of a substance, but the chemical composition of the substance remains the same
Explanation:
Physical change mainly physical properties of a substance while the chemical changes remain unchanged. Once there is a change to the chemistry of the substance, this would be classified as a chemical change.
Which term describes the total internal energy of a material due to the motion
of its particles?
A. Nuclear energy
B. Thermal energy
Ο Ο Ο
C. Electrical energy
D. Chemical energy
Answer:
Thermal Energy
Explanation:
Thermal energy is the total internal kinetic energy of an object due to the random motion of its atoms and molecules They consist of the sum of the internal kinetic energy (thermal energy) and the potential energy of an object.
Answer:
B. thermal energy.
Thermal energy or heat is due to the movement or vibrations of tiny particles such as atoms and molecules.
Explination:
Einstein proved the existense of atoms through his observation of Brownian Motion (the random movement of a dust particle, caused by it bumping into atoms).
how many valence electrons does P have?
Answer:
5 valence electrons
Explanation:
Phosphorus is in group VA so it has 5 valence electrons and Oxygen is in group VIA so each oxygen has 6 valence electrons.
In a molecule, how do we show what types of atoms are there and how many atoms there are of each type.
pls help i will give brainliest :)))) love youuuu
Answer:
i think the answer is C
Explanation:
if wrong im sorry
People who have certain lung diseases, such as emphysema or lung cancer, often have to use oxygen from tanks. A large volume of oxygen can be put into a small tank because oxygen is a gas, and gases can be_________.
Answer:
I believe the answer is compressed
Explanation:
The answer may be a slightly different word, but if it's looked at by a human and not a robot compressed should work too
Gases can be compressed by applying high pressure. Thus large volume of oxygen can be contained in a tank by compressing the gas with high pressure.
What are gases?Gases are substances in state where its molecules are located far apart and are able to spread in the surroundings. This property of spreading based on the concentration difference is called diffusion.
Thus, gases diffuse from high concentrated area to lower concentration region. Gaseous substances does not have a certain volume, mass or shape. But when they are collected into a container then the volume will be that of the container.
in liquid state, molecules are some more closer in comparison to gases and an intermolecular attraction of force bind these molecules together to have a certain volume and mass. Whereas in solids, all the molecules are tightly packed.
Gases can be liquified by applying high pressure at low temperature so that the distance between molecules can be decreased and an intermolecular force of attraction occurs there.
So that large volume of gases can be collected to a tank by compression using high pressure.
To find more about gas compression, refer the link below:
https://brainly.com/question/23026638
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Arrange in the correct order of occurrence. Write 1 – 5 for each statement.
___ Magma cools and sinks.
___ Rocks are heated and melt.
___ Magma expands and rises at divergent boundaries.
___ Some magma move sideways in opposite directions.
___ Subduction in convergent boundaries make plates to reach the mantle
Answer:
Explanation:Rocks are heated and melt.
Some magma move sideways in opposite directions.Magma cools and sinks.Magma expands and rises at divergent boundaries.Magma expands and rises at divergent boundaries.
what is the number of neutron in an atom of 86Kr
Answer:50
Explanation:
Kr has 36 protons because that is its atomic number. Simple subtraction from the given AMU gets 50 protons. ([tex]86-36=50[/tex])
Answer:
Neutron Number (N) 50
(I think)
Help me have no frewnds
Which of the following is an example of chemical energy being used?
(A) Battery in a flashlight
(B) Ice melting
(C) Riding a bicycle
(D) Mercury rising in a thermometer
Answer:
(A) Battery in a flashlight
Explanation:
Because the chemicals in the battery are being converted to light and heat energy from the bulb!
Answer: D
Explanatione: I hope this helped :)
The photo shows a seismograph. It is a machine that detects earthquakes
and makes graphs of the waves made by them.
What is the medium of the wave being detected by this seismograph?
A. Paper
B. Ink
C. Air
D. Rock
Answer:
D is the correct option.
Explanation:
A seismograph detects seismic waves which travel through the Earth, that is mainly rock(taking from the options given)
Answer:
It is just rock!
Explanation:
Convert 15.0 grams of H2 to molecules of H2.
Copy and complete the concept map using the following:
(Na, Fe, actinides, Hg, Cs, Alkali, Inner transition)
Answer:
a) Alkali
b) Na
c) Cs
d) Inner Transition
e) actinides
f) Fe
g) Hg
Explanation:
K, Na and Cs are all Alkali MetalsFe, Hg and Ag are all Transition Metalsactinides and lanthanides are known as the Inner Transition Metal. How many grams of water would require 4400 joules
of heat to raise its temperature from 34°C to 100°C?
The specific heat of water is 4.18 J/g.C
Answer:
The specific heat of water is 4.18 J/g C.
Explanation:
q
=
m
C
s
Δ
T
Never forget that!
2200
=
m
⋅
4.18
J
g
⋅
°
C
⋅
66
°
C
∴
m
≈
8.0
g
a sample of double-stranded dna contains 42% cytosine. approximately what percent of the nucleotides in this sample will be thymine?
Answer:
8% thymine
Explanation:
The percent of thymine in the given sample of the DNA will be equal to 8 %.
What is the structure of DNA?DNA, according to Chargaff, is composed of nucleotide subunits. These nucleotides are linked through two or more hydrogen-bonded to one another to form the double-stranded molecule of DNA.
The nucleotides found in the DNA molecule are Adenine, Thymine, Cytosine, and Guanine. Guanine (G) pairs with Cytosine (C) while Adenine (A) pairs with Thymine (T).
According to Chargaff's rule, the amount of Adenine is equal to that of Thymine in a DNA molecule and the same applies to Guanine and Cytosine. We can consider that the total amount of nucleotides equals 1 or 100%.
[tex]A + T + G + C = 100\%[/tex]
If Cytosine is 42 % of the DNA sample, this means that guanine will also be 42%.
G + C = 42 + 42 = 84%
A + T = 100% - 84 % = 16%
This means that Adenine and Thymine amount to 16 %. The amount of each nucleotide will be 16% ÷ 2 = 12% i.e. A = T = 8 %
Therefore, the percent of thymine in the given sample of the DNA will be 8 %.
Learn more about the structure of DNA, here:
https://brainly.com/question/22499464
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when it is time to end a reflux, first choose... and then turn off the heat. choose... until the system has cooled.
Answer:
second one is better
Explanation:
system is very much hot in first state..so wait for cooling down the system..but these depend on the organic compounds and products you are using. sometimes we need to carryout further steps in hot state..then you can't wail it to cool down
What can affect the properties of a substance?
neither the arrangement nor the types of atoms
only the types of atoms
the arrangement and types of atoms
only the arrangement of atoms
What Group is this Element in?
O Group 3
O Group 4
O Group 7
Group 1
Answer: group 7
Explanation: