Final answer:
Element x with a half-life of 7 minutes would take approximately 49 minutes to decay to 1 gram from 980 grams.
Step-by-step explanation:
The half-life of Element x is 7 minutes, which means that after every 7 minutes, half of the initial amount of the element will decay. According to the question, there are 980 grams of Element x. If we divide this amount by 2, we get 490 grams remaining after 7 minutes. Continuing this process, we can determine the time it takes for Element x to decay to a certain amount. To find out how long it takes for Element x to decay to 1 gram, we can set up an equation: 980 * (1/2)^(t/7) = 1. Solving this equation, we find that it takes approximately 49 minutes for Element x to decay to 1 gram.