Answer:
Homogeneous means composed of parts of different kinds; having widely different elements or components.
Explanation:
Answer: With few exceptions, the mitotic process ensures that this is the case. Therefore, mitosis ensures that each successive cellular generation has the same genetic composition as the previous generation, as well as an identical chromosome set.
Answer:C11 -----^boron+positron
Explanation:the above reaction is nuclear reaction.
Positron emission causes the decrease in atomic number by one.
As in above example carbon-11is converted into boron isotop which has atomic number of 5.
Answer:
Approximately 75%.
Explanation:
Look up the relative atomic mass of Ca on a modern periodic table:
There are one mole of Ca atoms in each mole of CaCO₃ formula unit.
- The mass of one mole of CaCO₃ is the same as the molar mass of this compound:
. - The mass of one mole of Ca atoms is (numerically) the same as the relative atomic mass of this element:
.
Calculate the mass ratio of Ca in a pure sample of CaCO₃:
.
Let the mass of the sample be 100 g. This sample of CaCO₃ contains 30% Ca by mass. In that 100 grams of this sample, there would be
of Ca atoms. Assuming that the impurity does not contain any Ca. In other words, all these Ca atoms belong to CaCO₃. Apply the ratio
:
.
In other words, by these assumptions, 100 grams of this sample would contain 75 grams of CaCO₃. The percentage mass of CaCO₃ in this sample would thus be equal to:
.
Answer:
When iron filings and sulphur powder are mixed and heated they undergo a chemical reaction and form ferrous sulphide (FeS). It is a new substance which has properties entirely different from Fe and S. Therefore, heating of mixture of iron and sulphur powder is a chemical change.