add answers with explanations

Author: Dipa-Sarker

Sprint-1/4-stretch-explore/chrome.md

@@ -11,8 +11,11 @@ In the Chrome console,
 invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
+// `alert` function deisplays a popup dialogue box with a message and the user have to click 'ok' button. 
 
 Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.
 
 What effect does calling the `prompt` function have?
+// `prompt` function displays a dialogue box with a message and asks the the user to give input.
 What is the return value of `prompt`?
+//It returns the value which user inputs. In the question it is myName.