1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Novosadov [1.4K]
3 years ago
9

Select all of the following events in which a chemical change occurs.

Chemistry
2 answers:
stira [4]3 years ago
8 0

Answer:

i believe it is all but c

Explanation:

mr Goodwill [35]3 years ago
8 0
B D and E are all chemical changes.
Sugar dissolving is a physical change because no new substance is formed it’s just sugar particles broken down smaller.
You might be interested in
Highlight the basic points in Lewis and Langmuir theory of electrovalency
ankoles [38]
The correct answer for the question that is being presented above is this one: "Electrovalency is characterized with the transferring of one or more electrons from one atom to another together with the formation of ions and as well as the number of positive and negative charges. 

The Lewis and Langmuir theory of electrovalency (and as well as Kossel's) is dealing with Ionic bonds. 

Lewis: electron-pair sharing, octet rule, Lewis Symbols or StructureLangmuir: introduced term "covalent" bond, and popularized Lewis's ideas

<span>The Lewis-Langmuir electron-pair or covalent bond is referred as the homopolar bond, where the complete transfer of electrons give rise to ionic, or electrovalent bond (1) through attraction of opposite charges.</span>
8 0
3 years ago
Plzz help guysss!! <br>How long would it take you to travel 8 miles at a speed of 1 mile per hour?​
GrogVix [38]

Answer:

ksjdhfbjkdfbvbdvb

Explanation:

6 0
3 years ago
Calculate the equilibrium number of vacancies per cubic meter for copper at 1000K. The energy for vacancy formation is 0.9eV/ato
nexus9112 [7]

Answer:

Therefore the equilibrium number of vacancies per unit cubic meter =2.34×10²⁴ vacancies/ mole

Explanation:

The equilibrium number of of vacancies is denoted by N_v.

It is depends on

  • total no. of atomic number(N)
  • energy required for vacancy
  • Boltzmann's constant (k)= 8.62×10⁻⁵ev K⁻¹
  • temperature (T).

N_v=Ne^{-\frac{Q_v}{kT} }

To find  equilibrium number of of vacancies we have find N.

N=\frac{N_A\ \rho}{A_{cu}}

Here ρ= 8.45 g/cm³  =8.45 ×10⁶m³

N_A= Avogadro Number = 6.023×10²³

A_{Cu}= 63.5 g/mole

N=\frac{6.023\times 10^{23}\times 8.45\times 10^{6}}{63.5}

   =8.01\times 10^{28 g/mole

Here Q_v=0.9 ev/atom , T= 1000k

Therefore the equilibrium number of vacancies per unit cubic meter,

N_v=( 8.01\times 10^{28}) e^{-(\frac{0.9}{8.62\times10^{-5}\times 1000})

   =2.34×10²⁴ vacancies/ mole

3 0
3 years ago
#1: Which of the following is the abbreviation for a unit of energy? A. K / B. °C/ C. W / D. cal............... #2: A 200 g bloc
stealth61 [152]
Among the choices, the unit of energy is calories. Answer in 1) is D. In 2) we are given with te mass , heat and temperature change. we just need to get the heat capacity and compare it with the following metals. The calculated heat capacity is 0.46 kJ/kg K. The answer is A. iron. In 3) we can compute the heat absorbed by the formula ΔH=mCpΔT. Cp of water is 4.18 J/g K. Answer of 3) is D. In 4) the formula used in Cp=ΔH/mΔT. Answer in 4) is A. The heat of enthalpy of fusion of ice is 80 cal/g. We convert this to J/g. Answer  in 5) is B.334 J/g.
8 0
3 years ago
Read 2 more answers
Which of the following processes have a ΔS &lt; 0? Which of the following processes have a ΔS &lt; 0? carbon dioxide(g) → carbon
Umnica [9.8K]

Answer:

All of the above processes have a ΔS < 0.

Explanation:

ΔS represents change in entropy of a system. Entropy refers to the degree of disorderliness of a system.

The question requests us to identify the process that has a negative change of entropy.

carbon dioxide(g) → carbon dioxide(s)

There is  a change in state from gas to solid. Solid particles are more ordered than gas particles so this is a negative change in entropy.

water freezes

There is  a change in state from liquid to solid. Solid particles are more ordered than liquid particles so this is a negative change in entropy.

propanol (g, at 555 K) → propanol (g, at 400 K)

Temperature is directly proportional to entropy, this means higher temperature leads t higher entropy.

This reaction highlights a drop in temperature which means a negative change in entropy.

methyl alcohol condenses

Condensation is the change in state from gas to liquid. Liquid particles are more ordered than gas particles so this is a negative change in entropy.

6 0
3 years ago
Other questions:
  • Someone send me a pic of a safety cartoon [drawn] neatly and all it needs is
    12·1 answer
  • What is the mole fraction of o2 in a mixture of 15.1 g of o2, 8.19 g of n2, and 2.47 g of h2?
    12·1 answer
  • Typical frequencies for several types of electromagnetic radiation are given below. Calculate the energy of each type of radiati
    9·1 answer
  • What type of electromagnetic waves does the human eye see as the colors red, blue, or green
    11·1 answer
  • Identify which location in the periodic table you would have the<br> largest atomic radii.
    8·1 answer
  • _____________ is the energy stored because of its position or shape.
    14·1 answer
  • Wwwwwwwwwwwwwwwwwwwwwwwwwwwww
    12·1 answer
  • A change that produces one or more ___________________ is a chemical change or chemical reaction.
    13·2 answers
  • 6. This particle has no charge<br> protons<br> neutrons<br> electrons
    14·2 answers
  • The period number of any element is equal to the number of its energy levels
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!