The first known telescopes, used around 1600, consisted of a lens and an eyepiece. today, telescopes are often computer controlled and consist of a complicated array of sophisticated lenses. which statement correctly describes how telescopes have changed over time? a.)the telescopes of the 1600s were used until the year 2000, when a more sophisticated telescope was built. b.)the telescopes of the 1600s were gradually improved upon over time, resulting in the telescopes that are available today. c.)the telescopes of the 1600s were used until the year 1900, when a more sophisticated telescope was built that was used until the year 2000. d.)the telescopes of the 1600s were abandoned after about 50 years, and the technology was completely replaced.

The correct option is option(B).

Explanation:

Telescopes which are used today are majorly different from the telescopes back in 1600.

With period of time. series of modification took place in an elementary design of a telescope which resulted in telescope we are using today which are controlled by computers and sensors so as to get precise picture of the distant objects.

Hence, the correct answer is option(B).

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.

i'm pretty sure it is letter c.) car