ElementAt

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        int[] numbers = { 1, 2, 3, 4, 5 };
        int third = numbers.ElementAt(2);
        int tenthError = numbers.ElementAt(9);  // Exception 
        int tenth = numbers.ElementAtOrDefault(9);  // 0
        Console.WriteLine(third);
        Console.WriteLine(tenth);
    }
}