As a general rule of thumb molecules where metals interact with non-metals tend to form ionic bonds (because they form oppositely-charged ions), while molecules where non-metals interact with non-metals tend to form covalent bonds (because they share electrons to fill valence shells). Some of the options listed refer to large polymers of more basic units - if you can identify the basic units, you can get a sense of the kinds of bonds you're dealing with.
Starch is a polymer of glucose. Glucose is an organic molecule made of C, H, and O (all non-metals). It contains COVALENT bonds.
Graphite is a carbon polymer (sort of). Carbon is a non-metal. It contains COVALENT bonds.
Paraffin wax is a mixture of long-chain hydrocarbons (lots of carbons stuck together with some hydrogens stuck around the edges). Non-metals again. COVALENT.
Copper nitrate is a metal (copper) and a non-metal (the polyatomic ion nitrate, NO3-). Therefore, copper nitrate as a whole is IONIC (be careful though - the N and O within the nitrate ion are both non-metals and so are bonded covalently, but they ultimately form an ion that is capable of forming ionic bonds with metals).
Iron oxide is a general term for some combination of iron (a metal) and oxygen (a non-metal). Regardless of the specific combination, the interaction is IONIC.
Sucrose is formed when glucose interacts with another sugar, fructose. Again, only C, H, and O are involved, so the molecule is COVALENT.
Calcium carbonate is similar to the copper nitrate situation - you have a metal (calcium) and a non-metal (carbonate) interacting though an IONIC bond. As with nitrate, carbonate (CO3[2-]) is itself a polyatomic anion containing covalent bonds between the C and O's, but forms ionic bonds because it is ultimately an ion.
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Atomic structure and Isotopes Quiz - Quizizz. The mass number of an element that has 18 protons, 18 electrons, and 19 neutrons<span> is The atomic number of an element that has </span>9 protons<span>, 9 electrons, and </span>10 neutrons<span> is</span>
1. s block elements have spherical s orbital as
their outermost orbital.
2. Since s orbital can accommodate a maximum of 2 electrons, each one of these elements have 1 or two electrons.
3. These s electrons are lost very easily to form
monopositive ions by Isoing one electron in the
outermost orbital or dipositive ions by losing 2
electrons.
4. They have low ionisation potentials and low electronegativities.
5. They are good conductors of heat and electricity, excepting H2 and He.
6. They are silvery, shiny metallic substances, (with the exception of hydrogen and helium which gaseous nonmetals).
7. They are malleable and ductile, i.e., we can
make sheets and wires from them, (exception:
H2, He)
8. They readily form ionic salts with most nonmetals.
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