Answer:
a: chemical change because the change cannot be reversed.
b: physical change because the action can be reversed.
c: chemical change.
d:chemical change.
any change that cannot be reversed is a chemical change and any change that can be reversed is a physical change.
Answer:
D) HCl(aq)
Explanation:
A homogeneous mixture can be defined as any liquid, solid or gaseous mixture which has an identical or uniform composition and properties throughout any given sample of the mixture. In Chemistry, all solutions are considered to be a homogeneous mixture.
In this scenario, the chemical formula which represents a homogeneous mixture is aqueous hydrogen chloride, HCl(aq). The aqueous hydrogen chloride is a homogeneous mixture of water and hydrogen chloride. This ultimately implies that, aqueous hydrogen chloride HCl(aq) is a solution of hydrogen chloride in water and it is commonly referred to as Hydrochloric acid.
Given by the chemical equation;
Democritus (460-370 BC) was a Greek philosopher who theorized that all matter could be reduced to particles that could not be divided, which he described as “atomos.”
John Dalton (1766-1844) Proposed the atomic theory.
Answer:

Explanation:
Given that,
The wavelength of a microwave is 7.42 mm or 0.00742 m
No. of photons, n = 359
We need to find the energy produced by this no of photons. It can be given by the formula as follows :

or

So, the required energy is
.