A picture. hope this helps at least a little.
Answer:
4g of the radioactive element present
Explanation:
Radioactive elements are atoms that are unstable in normal conditions and are converted in another different atoms.
1 half life express the time that is need to decay the half of the initial amount of the radioactive element.
If initially we have 8g of the radioactive element, after 1 life we will have 8g/2 =
4g of the radioactive element present
Answer:
Explanation:
The total energy or intrinsic energy of a system is called the enthalpy. In thermochemistry, we have two types of enthalpy changes which are:
- Exothermic changes
- Endothermic changes
For the freezing of water, the enthalpy change is an exothermic one. Exothermic changes are designated as negative. In this chemical change, heat is liberated to the surroundings and this leaves the environment at a much higher temperature. In freezing, the enviroment gains more heat as the material begins to cool to lower temperature.
Entropy is the degree of randomness or disorderliness of a system. When a phase change occurs from liquid to solid, freezing takes place. Such a change increases the orderliness of a system and entropy diminishes. Here, entropy is negative.
The free energy is a measure of the energy a system that does useful work. Free energy depends on enthalpy, entropy and temperature of a system. For phase changes such as freezing of water, the value of free energy change is 0.
For this process, an increases in temperature makes it non-spontaneous. Increasing temperature would alter the course of the reaction and makes it exothermic. For entropy, increasing temperature would increase entropy and therefore, the reaction would not be feasible.
Temperature would mostly affect the free energy. An increase in temperature would increase the value of entropy change and the reaction would not be spontaneous. With falling temperature value, the reaction becomes more spontaneous and favored.
The electronic configuration of the elements which share the group, must have the last electron in same block..
1%
Explanation:
The crust is the thinnest layer of the earth accounting for only 1% total volume of the planets.
Compositionally, the earth is divided into three layers which are the crust, mantle and the core.
- The crust is the outermost layer of the earth. It rich in silicate minerals. The rocks are classified into igneous, sedimentary and metamorphic rocks.
- The mantle takes up about 84% of the total volume of the earth. It is located in between the crust and the core. It is predominantly made up of ferro-magnesian silicate minerals.
- The cores accounts for slightly 15% of the volume of the earth. It is the center of our geoid shaped earth. It is rich in iron and nickel metals.
Learn more:
Mantle brainly.com/question/7623608
#learnwithBrainly
