Solutions of lead(ii) nitrate and potassium iodide were combined in a test tube. write a formula equation for the reaction.

yellow

When you mix solutions of lead (II) nitrate and potassium iodide. The precipitate is yellow in colour and the compound is lead (II) Iodide. Pb (NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq). Yes, it is a double displacement reaction.

Explanation:  The lead nitrate solution contains particles (ions) of lead, and the potassium iodide solution contains particles of iodide. When the solutions mix, the lead particles and iodide particles combine and create two new compounds, a yellow solid called lead iodide and a white solid called potassium nitrate. When a solution of potassium iodide is added to a solution of lead nitrate taken in a test tube, the precipitation of a yellowish solid is observed. This yellowish solid is lead iodide. Potassium nitrate is formed along with lead iodide.  When lead nitrate is mix with potassium iodine, a precipitation reaction occurs and yellow precipitate of lead iodide is formed.

what is the general relationship between a galaxy's distance from earth and its speed?

the answer is:

the farther away a galaxy is from us, the faster it is moving away from us.

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

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