The intensity of radiation of a radioactive substance was measured at half-year intervals. The results were: t (years) 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 1.000 0.994 0.990 0.985 0.979 0.977 0.972 0.969 0.967 0.960 0.956 0.952 where y is the relative intensity of radiation. Knowing that radioactivity decays exponentially with time: y(t) = ae-bt, estimate the radioactive half-life of the substance.

Hello, I need help on questions 4-7 if you can answer all of them? I gave you a data table and questions you can go ahead with. And the mass of NaCI is 12 grams.

11. Billy is running away from a Wells Fargo bank at a speed of 13 kilometers per hour (units are km/h). If the distance between the bank and the border to Mexico is 1.9 km, will he be able to get there before the cops arrive in 9 minutes? How long will it take for him to reach the border? (Hint: speed = distance / time, 1 hour = 60 minutes)

Perform the following mathematical function.51.11 + (0.97/2.414 × 0.32150 × e.-3.25) + 1.52444 3.4 The written value of 1.0 μm meansa. 102 mb. 10-2 mc. 106 m d. 10-6 m e. 10-9 m 1.2 An example of a physical property isA) the reaction of rubidium with water to form rubidium hydroxideB) the density of boronC) the burning of sulfur to form sulfur dioxideD) the reaction of cesium with oxygen to form cesium superoxideE) the energy content of liquid sodium

A solid is weighed on the balance using the following steps: 1. The balance is tared. 2. Weighing paper is placed on the balance and the mass displayed is 0.806 g 3. An object is added to the weighing paper and the mass displayed is 1.500 g What is the mass of the object?