042318 out of 20 a See page 48 18 Question 1 point Rutherfor

04/23/18 out of 20 a See page 48 18 Question (1 point) Rutherford\'s gold-foil experiment disproved Thomson\'s model of the atom and helped Rutherford to understand and explain some of the fundamental characteristics of atomic structure 1st attempt Part 1 (0.3 point) nl See Periodic Table Q See Hint How many protons,neutrons, and electrons are there in an atom of gold-1972 (Use numbers separated by commas to answer the question. For cxample, lithium-7 has 3 protons, 4 neutrons, and 3 electrons, so the answer would be 3,4,3) Part2 (0.3 point) 0 See Hint Which of the images below, (a) or (b), represents Thomson\'s proposed model for the structure of the atom? 1820 14 OF 20 QUESTIONS COMPLETED SUBMIT ANSWER

Solution

1.Gold 197, mass no(A) = 197 , atomic number (Z)= 79

Atomic no. (Z) = no.of electrons in an atom Therefore no. Of electrons in gold 197=79

No. Of electrons =no. Of protons Therefore no. Of protons in gold 197 is 79

Mass no. (A) = no. Of protons + no. Of neutrons

197 =79+ no. Of neutrons

No. Of neutrons = 197-79= 118

Ans: p=79,N=118,e- =79

2. According to Thomson atomic model famously known as watermelon model, there is a positively charged cloud all over an atom is evenly spread just like pulp of the watermelon and electron are stuck onto this positively charged cloud just like the seeds of the watermelon.

Ans: Hence the best suited Thomson model is model (a)

3. Rutherford experiment was bombardment of alpha particles to a gold foil, where maximum of the alpha rays passed through the gold foil, some deflected to different angles, and even some reflected back. From this he putforth a new theory that had a concept of having a nucleus where in the mass of an atom was concentrated.

Hence the appropriate statement about Rutherford experiment is

Ans: option b. Some alpha particles deflected to large angles as if they had stuck regions of highly positive charge and large mass.