Copper is a mineral and an element essential to our everyday lives. It is a major industrial metal because of its high ductility, malleability, thermal and electrical conductivity and resistance to corrosion. It is an essential nutrient in our daily diet. And, its antimicrobial property is becoming increasingly important to the prevention of infection. It ranks third after iron and aluminum in terms of quantities consumed in the USA.
Answer:
3. Equal numbers of protons and neutrons
Explanation:
The nucleus becomes unstable if the ratio of protons to neutrons is less than 1:1 or more than 1:1.5.
The most stable nucleus has a neutron proton ratio of 1:1 which means that they can not release a neutron or a proton to decay.
Nucleus 3 is therefore the most stable.
Answer:
Water is a compound. It contains more than one element
water is homogeneous
Answer:
The Lewis structures are shown in the figure
Explanation:
The lewis structure will be drawn using following steps
i) we will calculate the total number of valence electrons in the molecule
ii) will assign one bond (two electrons in between two atoms)
iii) then distribute the rest of the valence electrons as lone pair or shared pair based on completion of octet.
The structure of each molecule is given in the figure.
Valence electrons:

V.E = 5 +(2)6-1=16

V.E =5 +(2)6+7=24