Why has the southeast become a center for food processing

How does the viscosity of magma change as magma cools?

How many moles of oxygen gas are produced from the decomposition of six moles of potassium chlorate

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?