Which process results in a chemical change?

(1) tearing tin foil

(2) melting an iron bar

(3) crushing an aluminum can

(4) burning magnesium ribbon

What is a cathode? A. The electrode that releases ions into the solution B. The electrode at which a reduction reaction occurs C. The electrode that is oxidized in a redox reaction D. The electrode that donates electrons to the system

Write the number 345 in scientific notation, with the same number of significant figures: Write the number 345.0 in scientific notation, with the same number of significant figures:

If a hot air balloon has an initial volume of 1000 L at 50 ∘C, what is the temperature (in ∘C) of the air inside the balloon if the volume expands to 1700 L?

Which of the following molecules has one lone pair of electrons? a. ch4 b. hcl c. h2o d. nh3

Tekanan uap jenuh air murni pada suhu 20°C adalah 18 mmHg. apabila pada temperatur yang sama sebanyak 120 gram zat x dilarutkan dalam 990 gram air, tekanan uap larutan menjadi 17,37 mmHg, hitunglah massa molekul relatif zat x?

Which earth cycle does the suns energy drive

How many moles are in 10 grams of CaCl2?

Which is the correct formula for phosphorus pentachloride? PCl4 because a subscript of 4 indicates four Cl atoms PCl5 because a subscript of 5 indicates five Cl atoms P5Cl because a subscript of 5 indicates five P atoms P5Cl3 because a subscript of

Why are the elements in groups 3 to 12 often used to make dyes?

What is not needed for corrosion of metals? a. oxygen c. water b. ions d. sunlight