Answer:
The correct answer choice is A. A chemical change has occurred because new compounds have been produced.
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.Example: Melting of ice A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.Example: photosynthesis
Photosynthesis is the process used by plants, algae and certain bacteria to convert energy from sunlight and turn it into chemical energy in the form of glucose which is used a s a source of energy by many organisms.
Thus the true statement is a chemical change has occurred because new compounds have been produced.
Can someone please help. I have no idea how to do this
Explanation:
c-o number if electrons shared: 4. doubke bond. non polar
c-cl 2 electrons sharde single bond non polar
I know this cause one dash equals 2 electrons chemistry teachers use them when two compounds are sharing electrons rather then using two dots so people know the difference
Explain in your own words:
i. Sublimation
ii. Condensation
iii. Melting
what are the solar home lighting
Answer:
Sunlight
Explanation:
Home lighting System is powered by solar energy using solar cells that convert solar energy (sunlight) directly to electricity. The electricity is stored in batteries and used for the purpose of lighting whenever required
What test was used to identify hydrogen gas? Write a balanced equation to represent the test?
Chose any ONE state of matter and explain the space of the particles.
Use a drawing to help explain.
Answer:
solid
intermolecular space is very closed to each other and tightly packed
What can a scientist use to observe very small things?
1. A good pair of glasses
2. Tools and technology
3. The five senses
4. Sense of touch
Answer:
2
Explanation:
depends on how small but you wouldn't be able to see with good glasses your senses or your touch
Answer:
Tools and Technology ( Microscopes etc)
Explanation:
Glasses are not good enough to see on the molecular and cellular level.
The five senses aren't reliable and can vary between people.
Touch is one of the 5 senses, and touching chemicals isn't good.
please help me!! DUE TOMORROW :(
Answer:
It’s in the photo, sorry if it’s really messy!
Explanation:
Please ask if you have any questions!
Name three sources of atmospheric carbon dioxide.
Answer:
Natural sources include decomposition, ocean release and respiration. Human sources come from activities like cement production, deforestation as well as the burning of fossil fuels like coal, oil and natural gas.
An ammonia solution has a pH of 8.25. What is its [OH-]?
pH + pOH = 14
If pH=8.25, then:
pOH = 14 - 8.25 = 5.75
pOH = -log[OH-]
5.75 = -log[OH-]
-5.75 = log[OH-]
10^(-5.75) = [OH-]
[OH-] = 0,0000017783
[OH-] = 1,78×10^(-6) mol/dm³
convert 8.4 • 10^16 molecules of CO2 to moles
Answer:
0.00000000000000084
Explanation:
Which statement is false?
a. The density of a gas is constant as long as its temperature remains
constant.
b. Gases can be expanded without limit.
c. Gases diffuse into each other and mix almost immediately when put into the
same container.
d. The molecular weight of a gaseous compound is a non-variable quantity.
26. Which group in the periodic table contains
an element that can form a blue sulfate
a
compound?
(1) 1
(2)
(3) 11
(4) 17
Answer:
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Answer:
Option (3) 11
Explanation:
Elements in Group 11 of the periodic table are called Noble Metals.Noble metals have high resistance to oxidation and low chemical reactivity.Noble metal includes Gold (Au), Silver (Ag), Copper (Cu).Copper forms a blue sulfate when reacts with Sulphuric Acid.Formula of Copper Sulfate : CuSO4.Since, Copper belongs to the Group 11 elements of the periodic table hence, option (3) is the right answer.For more information:
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How many decigrams of chromium are in 3.19 x 10^23 atoms of chromium? show work
mol = 3.19 × 10^23/6.02^23
= 0.529 mol
mass = 0.529 × 52
= 27.508 g
g to decigram
= 27.508 × 10
= 275.08 decigram
If 10.0 kg of water occupies 10.0 liters, what is the volume in quarts?
how many compounds can I make with sodium, hydrogen, oxygen?
will give brainliest and 100 points to the correct answer
Answer:
маны
Explanation:
Answer:
2H2 + O2 → 2H2O
Explanation:
is the effect of hot and cold water on acid different?
Answer:
When the acid is mixed with the water, an immediate chemical reaction takes place. The formation of carbon dioxide causes breakdown of the sample into finer particles.
The heat in the Stomach rises up, causing esophageal reflux, chronic sinusitis, headaches, eye disorders and problems with the teeth. Furthermore, ingesting cold water creates moisture or “dampness.” Bacteria, candida, and parasites thrive in damp areas, especially in your stomach and uterus.
What is the wavelength, in nanometers, of light with a frequency of 1.97x10^15 Hz?
a) 1.52 nm
b) 1.52x10^-7 nm
c) 152 nm
d) 15.2 nm
Which of the following ideas did Greek philosopher Democritus contribute to the atomic theory?
A. Matter is composed of only one kind of particle, which can be easily destroyed.
B. Every element has a specific type of atom, which remains the same size in all forms of matter.
C. All matter is composed of small particles, which combine to make larger objects.
D. Each object is made up of one atom, which varies in size from very small to very large.
I will mark the correct answer the brainliest
Answer:
c. all matter is composed of small particles,which combine to make larger objects
List the four quantum numbers
Answer: In atoms, there are a total of four quantum numbers: the principal quantum number (n), the orbital angular momentum quantum number (l), the magnetic quantum number (ml), and the electron spin quantum number (ms).
Answer:
(n)
(i)
(mı)
(ms) s is suppose to be smaller than the m
Explanation:
the principal quantum number (n)
the orbital angular momentum quantum number (I)
the magnetic quantum number (ml)
the electronic spin quantum number (ms)
Which statement best explains the purpose of using a mole in the measurement of matter? It is commonly used as another unit of mass. It allows chemists to deal with a large number of atoms. It is used only for studying the properties of gases. It explains that substances with the same moles have the same mass.
Answer:
B) It allows chemists to deal with a large number of atoms.
Explanation:
On Edge 2022
The statement which best explains the purpose of using a mole in the measurement of matter is that it allows chemists to deal with a large number of atoms.
What is a mole?Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons .Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
Learn more about mole,here:
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increasing temperature increases:
1:Enthalpy
2:Free Energy
3:Entropy
4:Specific heat
Answer:
2 :free energy
Explanation:
I hope it is fine answer for you ☺️☺️☺️
what is the name of the compound ZnO
Which of the following is a challenge of prosthetic engineering that has been met through tissue engineering?
- Predicting failure
- Biocompatibility
- Strength
- Power
Answer:
Biocompatibility
Explanation:
I’m a genius and it’s the answer :D
Biocompatibility is a challenge of prosthetic engineering that has been met through tissue engineering. Hence, option B is correct.
What is Biocompatibility?Biocompatible materials are used in medical devices, such as menstrual cups, stents, or ventilators.
A biocompatibility problem might happen when some of the materials are trapped in the patient's gingival sulcus.
Tissue engineering is an important field of regenerative medicine for tissue repair (after damaged caused by a disease or an accident, for example).
To offer this possibility, stem cells are important tools owing to their capacity to differentiate into a large number of cells according to the stimuli provided.
Hence, option B is correct.
Learn more about Biocompatibility here:
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50 PTS!!!! No links pls!
What is a title name for Aerobic cellular respiration?
Answer:
Like another name?
Aerobic cellular respiration is also called aerobic metabolism, cell respiration, and oxidative metabolism.
Explanation:
4) Calculate the percentage by
mass of oxygen in Pb(NO3)2
A) 193
B20
145
Answer:
im getting 331.23
Explanation:
Element Number Mass Percet Composition
O 6 16.00 28.9828819853274
N 2 14.01 8.45937867946744
Pb 1 207.21 62.5577393352051
I have a problem with solving this type of chemistry problem. Please Help!
What is the stock name for chromic ion
Answer:
Chromium(III)
PubChem CID 27668
Structure Find Similar Structures
Chemical Safety Laboratory Chemical Safety Summary (LCSS) Datasheet
Molecular Formula Cr+3
Synonyms Chromium(III) Chromic ion chromium(3+) CHROMIUM (III) Chromic cation More
what is wrong with the statement? "because there are no common factors in the molecular formula, k2co3 is also the empirical formula of potassium carbonate"
The empirical formula is the same as the molecular formula because the ratio of atoms in the compound correspond to the number of atoms of each element in the compound.
The empirical formula of a compound shows the ratio of atoms of each element in the compound while the molecular formula shows the number of atoms of each element in the compound.
For the compound, K2CO3, the empirical formula is the same as the molecular formula because the ratio of atoms in the compound correspond to the number of atoms of each element in the compound. It has nothing to do with common factors.
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Your teacher asks you to prepare 500 mL of a 2.75 molar solution of NaCl for an upcoming
laboratory experiment. Write a step-by-step procedure describing how you would carry out
this task.
To prepare 500 mL of a 2.75 molar solution of NaCl, measure 80.44 g of NaCl, place it in a 500 mL volumetric flask and fill it with water to the mark.
We'll begin by calculating the number of mole of NaCl in the solution
Volume = 500 mL = 500 / 1000 = 0.5 L Molarity = 2.75 MMole of NaCl =?Mole = Molarity x Volume
Mole of NaCl = 2.75 × 0.5
Mole of NaCl = 1.375 mole
Next, we shall determine the mass of 1.375 mole of NaCl.
Mole of NaCl = 1.375 mole Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol Mass of NaCl =?Mass = mole × molar mass
Mass of NaCl = 1.375 × 58.5
Mass of NaCl = 80.44 g
Therefore, to prepare 500 mL of a 2.75 molar solution of NaCl, measure 80.44 g of NaCl, place it in a 500 mL volumetric flask and fill it with water to the mark.
Learn more about molarity: https://brainly.com/question/6685468
A substance has a molar heat of combustion of -810.4 kj/mol. when 0.285 mol of the substance is burned in a calorimeter containing 8.60 kg of water, the increase in water temperature is:
Answer:
6.42 °C
Explanation:
Q = mcΔT
Q = energy gain/release (J)
m = mass (kg)
c = specific heat capacity (J/°C/kg)
ΔT = change in temperature (°C)
Qs = n(ΔH°c)
Qs = energy gained/released from substance (kJ)
n = moles (mol)
ΔH°c = molar heat of combustion (kJ/mol)
m = 8.60
n = 0.285
ΔH°c = -810.4
c (of water) = 4184
Qs = 0.285(-810.4)
Qs = -230.964 (or -230964 J)
Q = 230964
230964 = (8.60)(4184)ΔT
230964 = 35982.4(ΔT)
ΔT = 6.4188... °C → 6.42 °C