input: Write a function to check if an element exists within a given list of integers. If the element exists within the list return True, else return False. If the list is empty return False.
  assert element_exists(3, [1, 2, 3, 4, 5])==True
  assert element_exists(6, [1, 2, 3, 4, 5])==False
  assert element_exists(0, [])==False
  assert element_exists('a', [1, 2, 'a', 4])==True
  assert element_exists(None, [None, 2, 3])==True
output: def element_exists(element, lst):
      return element in lst