Answer: (2) CO
Co, Cr, and Cu are elements. Elements cannot be broken down by a chemical change, but compounds can. Since CO is a compound, it can be decomposed by a chemical change.
The last question depends on the scientific method.
Scientific Method
1. Make an observation of what u are testing 2. Form a question about ur observations. 3. Make a hypothesis 4. Conduct your experiment 5. Record information and results.
The first question depends what you will need to use first for the experiment.
Answer:
Scandium
Explanation:
Mendeleev played an important role in the development of the modern periodic table. His periodic table was filled with gaps. He said that these gaps were elements that were yet to be discovered. He rightly predicted many elements which have now been discovered and fitted in their proper places in the periodic table.
He used the prefix ''eka'' to refer to elements whose properties were alike but were yet to be discovered at that time.
The compound named ekaboron which he predicted to have an atomic weight between 65 (zinc) and 75 (arsenic) with a valence similar to aluminum was later discovered in 1879 and properly named scandium.
Answer:
Mg(OH)2(s) + 2HCl(aq) → 2H2O(l) + MgCl2(aq)
Explanation:
