Answer:
i) Rusting occurs the least in tubes 2 and 3 because either of air and water which are necessary for rusting is absent in the two tubes respectively.
ii) Rusting occurs most in tube 1 because both air and water which are necessary for rusting are present.
Explanation:
Rusting is a chemical change which involves a redox reaction. During the process of rusting, metallic iron is oxidized to hydrated iron (iii) oxide by oxygen present in air.
For rusting to take place effectively, each of these three factors mist be available: metallic iron, oxygen and water.
In the figure above, the iron nails in the three tester tubes will rust to different extents based on the availability of the three factors.
In test tube 1, the iron nails will rust the most because all the three factors: metallic iron, oxygen present in air, and water are abundantly present.
In test tube 2, the iron nails will rust the least or not at all because boiling of water removes dissolved oxygen from water and the oil layer above the boiled water prevents entry of oxygen from air. Thus, the nail do not rust because one of the three factors for rusting to take place, in this instance, oxygen is absent.
In test tube 3, the iron nails rusts the least or not at all as well because moisture or water is absent. Calcium chloride, a drying agent removes all the moisture from inside the tube. Hence, even though air is present, rusting do not occur as there is no moisture or water present.
Answer:
Plato Answer
Explanation:
Embryonic stem cells are plentiful, and they can create every cell in the human body. Researchers can use these cells to create tissues. They can possibly grow new organs in a lab to treat diseased organs. Adult stem cells are rarer in the human body, and they’re limited in the types of cells they can make.
An embryo can’t grow without its stem cells, so people have ethical concerns about their use. Adults can provide consent to donate their stem cells, so there are fewer ethical issues regarding the use of adult stem cells.
Animals don’t need to absorb sunlight in order to live. Only plants have chloroplasts to absorb the rays from the sun which is required for them to live and grow
Answer:
The pain nerves in her hand go to the brain to notify it. The brain processes this information and decides to tell the hand to remove itself from the stove. Then, the brain sends this signal back to the hand to make it remove tself from the stove.
Explanation:
Answer:
This question is incomplete as it lacks statements, the statements and the answers are as follows:
occurs in organisms that sexually reproduce - MEIOSIS
occurs during growth and development - MITOSIS
the DNA is replicated - MITOSIS AND MEIOSIS
occurs in all organisms - MITOSIS
the number of chromosomes remains the same - MITOSIS
the number of chromosomes reduces by half - MEIOSIS
Explanation:
Meiosis and mitosis are both types of cellular divisions that occur in living cells. Mitosis involves the formation of two (2) daughter cells that are genetically identical to the parent cell while meiosis involves the formation of four (4) daughter cells that are genetically different from the parent cell.
The following are characteristics of the two division processes based on this question:
MITOSIS:
- It occurs during growth and development of an organism.
- it involves DNA replication
- it occurs in all organisms since every living organism undergoes growth and development.
- the number of chromosomes after mitosis remains the same in the daughter cell i.e. 2n remains 2n
MEIOSIS:
- It occurs only in organisms that sexually reproduce.
- it also involves the replication of DNA
- The number of chromosomes in the daughter cells is reduced by half i.e. 2n to n.
