How many atoms are present in 2g of hydrogen gas​

Predict the products butane (c4h10) + oxygen —>

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space

Chemistry worksheet - i am not sure what they are asking for exactly?