Question

An atom of an element is represented as 19 X 39 i. What does value 39 indicate? ii. What does value 19 indicate? iii. What is the number of protons in X? iv. What is the number of electrons in X? v. What is the number of neutrons in X? vi. Is element X metal or non-metal?

Answer 1

Answer:

39 is mass number....19 is atomic number....no. of proton is equal to at. no. i.e. 19

Explanation:

4) e- are equal to proton in neutral atom ..so 19..

5)neutrons are 39 -19 =20....6) 19 atomic no. is of potassium which is metal

Answer 2

Explanation:

Kerala atom of an element is present as 19 in 239 what does value of 39 indicates