D. Physical change
Cause you are the one doing the change to it and physical change means You.
Answer:
Option B is correct.
The net ionic chemical reaction when Cu(NO₃)₂ reacts with water is
Cu²⁺(aq) + H₂O(l) ⇌ Cu(OH)¹⁺(aq) + H¹⁺(aq)
Explanation:
When ions dissolve in polar solvents (in water especially), then often attract ions of opposite signs.
Cu(NO₃)₂ dissolves into Cu²⁺ & NO₃⁻ and water contains H¹⁺ & OH⁻
The Cu²⁺ attracts the OH⁻ from water, thereby giving the Cu(OH)¹⁺ ion (with a net charge of +2-1 = +1) and the NO₃⁻ takes up the H⁺ ion.
Answer:
they have an equal number of positive and negative charges
The research of astronomy during the time period of 1970 - 1990 is given below:
<u>Date</u> <u>Event</u>
1. 15 June 1974 Black Brant VC sounding rocket from White Sands.
2. 14 May 1973 Launch of Skylab, the USA's first space station
3. 26 July 1971 Launch of Apollo 15
<h3>What is Astronomy?</h3>
This refers to the branch of science that deals with celestial bodies and their relation to each other.
Hence, from information about astronomy, between the time period 1970 - 1990 as it was on the 26th of December, 1974 that the Soviet space station Salyut-4 was launched.
The event I think had the greatest impact in astronomical history during this time period was the launch of Apollo 16.
Read more about astronomy here:
brainly.com/question/1141458
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