I) Predict what will happen to the size of metal calcium and give a reason for your answer. ii) Why did the phenolphthalein change colour?

111) What can you conclude from the pop sound given off?

iv) Explain why the pop sound was not produced in the other two test tubes.

pla·gia·rism

/ˈplājəˌrizəm/

learn to pronounce

noun

the practice of taking someone else's work or ideas and passing them off as one's own.

explanation:

the solar system used to have much dust particles option no d

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

it's c (engineer's do their work with mechanical stuff not on any living being)