Use blue litmus paper. This is an indicator that can safely determine whether it is a base or an acid by changing color in response to the substance. This color indicates whether it is an acid or a base. Refer to the pH scale to see if the substance is basic or acidic.
What is the percent by mass of sodium in Na2SO4? total mass of element in compound molar mass of compound Use %Element x 100
Lava I think try that hope it helps :)
The more kinetic energy a substance has, the warmer it will be and the faster particles will be moving, which reduces the density of the substance
