Phương trình hóa học: 2Mg+O2->2Mgo
option of d is the write answer
- Compounds are formed when two or more <u>elements</u> are chemically combined.
- When these elements are <u>chemically</u> combined, a new substance is formed with new chemical and physical <u>properties</u>.
- An element is a <u>pure</u> substance that cannot be separated into simpler substances by <u>physical</u> or chemical means.
- A compound is two or more elements <u>combined</u> chemically to produce a new substance.
- When two or more elements chemically combine, the compound has new properties, different from the chemical and physical properties of the <u>original</u> elements.
<h3>What is a chemical element?</h3>
A chemical element can be defined as a pure substance which comprises atoms that have the same atomic number (number of protons) in its nuclei and as such it is the primary constituent of matter.
Generally, some examples of a chemical element include the following:
- Argon.
- Sodium.
- Carbon.
- Oxygen.
- Hydrogen.
- Phosphorus
- Copper
- Aluminum
- Potassium
- Magnesium
<h3>What is a pure substance?</h3>
A pure substance can be defined as a single sample of matter that cannot be separated into other kinds of matter through the use of any physical or chemical separating technique because it has distinct chemical properties and a definite and constant composition.
Read more on pure substances here: brainly.com/question/2056940
#SPJ1
Ni solution could be used to remove lead from lead (II) nitrate.
Explanation:
The removal of lead from lead nitrate will take place by displacement reaction.
In displacement reaction less reactive element is displaced by more reactive element form it compound.
The reactivity is decided by the placement of metal in the activity series.
A metal which is at higher position in the activity series will be able to displace the metal or element having lower position.
From the options given we will check their position in the activity series in comparison to Pb
Cu is lower in series than Pb hence cannot displace.
Hg is placed lower in the series than Pb hence cannot displace Pb.
Ag is placed lower than Pb in the series hence cannot displace Pb.
Ni is placed above the Pb in activity series hence can displace lead.
