Answer:
The mass percent of copper as element is the same.
Explanation:
First of all we need the reaction that is presented below:
→ 
The mass percent of copper (Cu) as element is the same because of during the reaction the element only transform its nature from copper carbonate (
) to copper oxide (
), the latter is a solid and will remain in the system.
On the other hand, you will note that the global percentage mass will be small because of the reaction produce (
) that is a gas and this one will escape for the system.
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Answer: a) 
b) 1 mole of
is produced.
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The skeletal equation is:

The balanced equation will be:

Thus the coefficients are 2, 3 , 10 , 4 , 3 , 2 and 5.
b) Oxidation: 
Reduction: 
Net reaction: 
When 1 mole of
is produced, 1 mole of
is produced.
The question is incomplete as it does not have the options which are:
A) anaphase
B) prophase
C) telophase
D) metaphase
E) interphase
Answer:
The correct answer will be option-D
Explanation:
Colchicine is a drug obtained from the <em>Colchicum autumnale</em> which is a poisonous European flowering plant. The drug is used to treat joint swelling and gout.
Colchicine shows its effect during the cell division cycle especially during the division of nuclear content. When the cell is in metaphase and is preparing for the anaphase, the colchicine inhibits the polymerisation of the microtubules. The inhibition of microtubules inhibits the assembly of the mitotic spindle as a result of this the DNA do not move into new daughter cells.
Thus, option-D is the correct answer.
Answer:
It has been approximately 6 hours after death.
Explanation:
This is because between 2-6 hours after death, the body starts becoming stiff from top to bottom, then spreading to the limbs. Since there is only rigor in his upper body, that would mean that with normal temperature and body conditions, it would be 4 or 5 hours after death. But since he is obese and in cold temperature, there is slower progression of rigor, leading to the maximum time in the first rigor mortis phase, 6 hours.
Answer: Option (B) is the correct answer.
Explanation:
A covalent compound is a compound formed by sharing of electrons. And, in a covalent network solid atoms are bonded by covalent bonds in a continuous network that is extending throughout the material or solid.
This continuous arrangement of atoms are like a lattice.
For example, diamond is a covalent network solid in which carbon atoms are arranged in a continuous lattice like structure.
Hence, we can conclude that the statement all the atoms are covalently bonded to other atoms to form a lattice-like structure, best describes the structure of covalent network solids.