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
Len [333]
3 years ago
12

The images below show two commonly observed changes.

Chemistry
2 answers:
Bas_tet [7]3 years ago
8 0
The correct answer is:  [A]: 
________________________________________________
                   "Picture I shows a chemical change, because a new                               substance is formed."
__________________________________________________________
Note:   "Picture II" is a "physical change" because it is a "phase change"—no "new substance" is form; rather, the same substance changes form.
__________________________________________________________
dolphi86 [110]3 years ago
3 0

Answer. The correct statement is (A).

Explanation: In first figure chemical change is taking place. Large iron pipes after exposure to atmosphere resulted in the formation of rust on iron pipes. Rusting happens due to reaction between iron and oxygen with formation of a new substance that is iron(III)oxide which is reddish brown in color.

                    4Fe(s)+ 3O_{2}(g)\rightarrow 2Fe_{2}O_{3}(s)

In second figure there is a change in state of substance which has changed from liquid state to solid state. Only arrangement of molecules has changed. As in liquid state molecule are free to move and weakly associated with each other where as in solid state movement of molecule are restricted.



You might be interested in
Write a balanced chemical reaction for the dissolution of your copper oxide sample in hydrochloric acid
masha68 [24]
Copper oxide reacts with hydrochloric acid to produce copper chloride and water.

So the basic equation that illustrates this reaction is:
CuO + HCl ......> CuCl2 + H2O

Now, we need to balance this equation:
the number of copper and oxygen moles are balanced.
For each of hydrogen and chlorine, we have one mole as a reactant and two moles as product.
Therefore, to balance this, we will add an extra mole of HCl in the reactants.

Based on this, the final balanced equation would be:
CuO + 2HCl ................> CuCl2 + H2O
5 0
3 years ago
Convert 4.50 moles of Fe to atoms of Fe
olya-2409 [2.1K]
Each mole of a substance contains 6.02 x 10²³ particles
Atoms of Fe = 4.5 x 6.02 x 10²³
= 2.709 x 10²⁹ atoms
7 0
3 years ago
What's the answer to number 5? I need the answer quickly please
Anton [14]
That's because <span>the specific heat capacity of water is higher than specific heat capacity of iron, meaning that the water would need to lose more heat energy to drop its temperature.</span>
4 0
4 years ago
Help me. ASAP!!!!! 23 POINTS!!!!!!!
Alona [7]
a) Group 2 elements have 2 electrons on their outer shell, so they form a 2+ charge.

b) they lose 2 electrons as they are transferred to the non metal.

c)They obtain this charge as when they are made into an ionic compound the 2 electrons on the outer shell are transferred to the non metal, meaning there are 2 more protons that electrons, giving it a positive charge.

hope this helps! :)
6 0
3 years ago
For some hypothetical metal, the equilibrium number of vacancies at 600°C is 1 × 1025 m-3. If the density and atomic weight of t
Mashcka [7]

Answer:

fraction of vacancies for this metal FV = 1.918*10⁻⁴

Explanation:

Given:

The number of vacancies per unit volume => ( Nv = 1*10²⁵ m⁻³ )

But we know that Avogrado's constant NA = 6.022*10²³ atoms/mol

Density of the material is given in g/cm3 we need to convert it to g/m³

Density of material ( p ) in g/m³ :

To convert we know that

1 g/cm³ = 1000000 g/m³ then

7.40 * ( 1000000 ) = 7.40*10⁶ g/m³

So, Density of material ( p ) in g/m³ = 7.40*10⁶ g/m³

Given Atomic mass = 85.5 g/mol

To Calculate the number of atomic sites per unit volume , we will use the below formula by substituting those values above

N = NA * p / A

N = ( 6.022*10²³ ) * ( 7.40*10⁶ ) / 85.5

N = 4.45*10³⁰ / 85.5

N = 5.212*10²⁸ atoms/m³

We can now Calculate the fraction of vacancies using the formula below;

Fv = Nv / N

Fv = 1*10²⁵ / 5.212*10²⁸

fraction of vacancies for this metal at 600c.= 1.918*10⁻⁴

8 0
3 years ago
Other questions:
  • Which is the best example of technological design
    12·1 answer
  • What is the answer to this question please
    9·2 answers
  • Which of the following is a unit of mass ?
    6·2 answers
  • in carbon tetrachloride proceeds as follows: 2N2O5→4NO2+O2. The rate law is first order in N2O5. At 64 ∘C the rate constant is 4
    10·1 answer
  • Analyze: What do the elements in each column of the periodic table have in common?
    6·1 answer
  • A student is carrying out a biological preparation that requires 1 M NaCl to maintain an ionic strength of 1.0. The student choo
    11·2 answers
  • PLEASE HELP ME ASAP PLEASE!!!
    15·1 answer
  • Which agent most changes the earth's surface? O A. moving ice B. wave action O C. running water O D. tide action E. cloud moveme
    12·2 answers
  • What is the name of the molecule shown below?
    8·1 answer
  • What is the composition of an isotope of calcium (atomic number 20)?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!