Can someone help me with these two? (1) By approximately what factor would the mass of a sample of copper-66 decrease in 51 minutes? The half-life of copper-66 is 5.10 minutes.

(2) In 5.49 seconds, 1.20 g of argon-35 decay to leave only 0.15 g. What is the half-life of argon-35?

Identify one disadvantage to each of the following models of electron configuration: dot structures arrow and line diagrams written electron configurations type in your answer below.

Answer from each drop-down menu. e characteristics of a borane molecule (bh). the lewis structure and table of electronegativities are given olecular shape is and the molecule is reset next erved. search e a

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size