The image contains a word search puzzle. Identify and list all the hidden words.

Hidden Words:

• МЕНДЕЛЕЕВ (Row 2, Column 3, going right)
• КЛЕТКА (Row 3, Column 6, going down)
• ПЕРИОД (Row 8, Column 3, going right)
• Атом (Row 11, Column 5, going up)
• ЭЛЕКТРОН (Row 10, Column 9, going down)
• ЯДРО (Row 11, Column 1, going right)
• Протон (Row 13, Column 4, going up)
• Нейтрон (Row 13, Column 6, going up)
• Бор (Row 14, Column 1, going down)
• Гелий (Row 14, Column 1, going right)