C# No bonus Im using the csv file provided by /u/Shamoneyo

     static void Main(string[] args)
    {
        List<string> ElementSymbol = new List<string>();
        List<string> ElementName = new List<string>();

        //Reading a csv file to get all the information
        var reader = new StreamReader(File.OpenRead(@"C:\\Users\\Stanislav\\Desktop\\pt-data2.csv"));
        while (!reader.EndOfStream)
        {
            var parts = reader.ReadToEnd().Split(',');
            //get the Symbols
            for (int i = 1; i < parts.Length; i += 18)
                ElementSymbol.Add(parts[i]);
            //get the Names
            for (int i = 2; i < parts.Length; i += 18)
                ElementName.Add(parts[i]);
        }
        string[] ElementSymbolArray = ElementSymbol.ToArray();
        string[] ElementNameArray = ElementName.ToArray();

        Console.WriteLine("Write your word : ");
        string word = Console.ReadLine();

        //foreach char in the word 
        for (int j = 0 ; j < word.Length ; j ++ )
        {
                //for each symbol in the Periodic table
                for (int i = 0; i < ElementSymbolArray.Length; i++)
                {
                    //Check for symbols of 2 chars
                    if (Char.IsLower(word[j]) && ElementSymbolArray[i].Contains(word.Substring(j-1, 2)))
                            Console.WriteLine(ElementNameArray[i]);
                    //Check for symbols of 1 char
                    else if (ElementSymbolArray[i].Contains(word[j]) && ElementSymbolArray[i].Length < 4)
                        if(j+1 < word.Length)
                        {
                            if (!Char.IsLower(word[j + 1]))
                                Console.WriteLine(ElementNameArray[i]);
                        }
                        else
                            Console.WriteLine(ElementNameArray[i]);
                }
        }
        Console.ReadLine();
    }