An example of a base in chemistry would be like soap or lye
Answer:
B
Explanation:
The letter in this energy profile diagram of an exothermic change that signifies energy is B;
- An exothermic reaction is one in which heat is liberated to the surroundings.
- The surrounding becomes hotter at the end of the change.
- B is the enthalpy change of the reaction
- A is the activation energy
- C is the reactant
- D is the product
Answer:
4.375 milligram
Explanation:
Applying,
A = A'(2ᵃ/ⁿ)............. Equation 1
Where A = original amount of actinium-228, A' = amount of actinium-228 left after decay, a = Total time, n = half life
make A' the subject of the equation
A' = A/(2ᵃ/ⁿ)........... Equation 2
From the question,
Given: A = 70 milligram, a = 24.52 hours, n = 6.13 hours
Substitute these values into equation 2
A' = 70/(2²⁴°⁵²/⁶°¹³)
A' = 70/(2⁴)
A' = 70/16
A' = 4.375 milligram
32 electrons. as the orbitals get father away from the nucleus, they hold more electrons.
<span>Problem 1) From the given options the one that is proper of a chemist is the option B. testing a sample of water form a well. This activity belongs to the field called analytical chemistry which uses special techniques (instruments and processes) to study (separate, identify and quantify matter).
Problem 2) The only of the given procedures that involves a physical change in one substance is the option D. grinding chalk into a fine powder. In this process the molecules remain being the same (same atoms bonded in the number and way).</span>
