What element has the electron configuration 1s2 2s2 2p6 3s2 3p1?

How do i turn 2 s into one in the products

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?

What occurs when a cell engulfs large food particals