Radioactive decay => C = Co { e ^ (- kt) |
Data:
Co = 2.00 mg
C = 0.25 mg
t = 4 hr 39 min
Time conversion: 4 hr 39 min = 4.65 hr
1) Replace the data in the equation to find k
C = Co { e ^ (-kt) } => C / Co = e ^ (-kt) => -kt = ln { C / Co} => kt = ln {Co / C}
=> k = ln {Co / C} / t = ln {2.00mg / 0.25mg} / 4.65 hr = 0.44719
2) Use C / Co = 1/2 to find the hallf-life
C / Co = e ^ (-kt) => -kt = ln (C / Co)
=> -kt = ln (1/2) => kt = ln(2) => t = ln (2) / k
t = ln(2) / 0.44719 = 1.55 hr.
Answer: 1.55 hr
Answer:
2.Closed System: A closed system is a thermodynamic system where energy can be exchanged with its surrounding but not matter. Open System: Open systems can exchange matter with the surrounding. Closed System: Closed systems cannot exchange matter with the surrounding. Open System: The mass of the system will vary with time in open systems.
Explanation:
1.The particle model is the name for the diagrams used to draw solids, liquids and gases. In the model, the particles are shown as circles or spheres. However, the particles in ice, liquid water and steam look the same because they are all water, but in different states of matter. Why do we use the particle model in science?
3.An open system can be defined as a system which can exchange both matter and energy with the surrounding. For example, the earth can be recognized as an open system. In this case, the earth is the system, and space is the surrounding. Sunlight can reach the earth surface and we can send rockets to space.
Answer C is for kg and but it's .00134 for grams
The answer should be A, flammability.
The isotopes of the same element would result in the same chemical properties, as the number of protons and electrons are not changed, meanwhile, the physical properties would be slightly different with each other because they have different numbers of electrons.
Out of the 4 options, only option A is a chemical property. Chemical properties are the properties of an element reacting with other substances that creates new substances at the end. While physical properties are the ones that does not produces new substances or any reactions. They are usually observable and measurable.
Therefore, since flammability is a chemical property, the answer is A.
Answer:
2. Na2O
Reasoning:
Na (soduim) is the only metal out of all the elements in the answer choices, and is bonded with oxygen, a nonmetal, therefore creating an ionic bond.
