Remember, covalent compounds are compounds with bonds between two non-metals. Ionic bonds are those between a metal and a non-metal.
To determine if an element is a metal or non-metal, simply look at the periodic table! So...
a. Li is found on the left side while F is found on the right. A bond between a metal and a non-metal. This is an ionic bond.
b. Mg is found on the left side while S is found on the right. A bond between a metal and a non-metal. This is an ionic bond.
c. This is a tricky one. ammonia, or NH3, is covalent. You just have to remember this one. It has no net charge, unlike its brother NH4 (which has a 1+ charge put is still covalently bonded). Hydrogen has weird properties!
d. Ca is found of the left side while Cl is found on the right. A bond between a metal and a non-metal. This is an ionic bond. Also consider the charges! Ca has a charge of 2+ but Cl only has a charge of 1-. This is why there are 2 Cloride atoms.
No, because HPO₄ is a multi-atom ion and has its own name which is Hydrogen phosphate.
Since the mass of a single popcorn kernel is not given, lets us assume that it is 1 gram
Now:
1 mole of popcorn kernels contain kernels
Since:
1 kernel weighs 1 gram
Then,
kernels would weigh grams
First, there is nothing inherently different about transuranic elements. They do share some common characteristics. As a class, they are all radioactive. But that's also true of all elements above atomic number 82 (lead) (Pb-208 being the heaviest stable isotope known). And radioactivity is actually far more common than stability if you look at all the known nuclides. The transuranics also share the trait that they will undergo nuclear fission. We'll look at that later, also check the link for more info. But these traits are not unique to the transuranics. Uranium is also fissionable, and elements as light as atomic number 88 (radium) may undergo fission (but not very efficiently). We also should keep in mind that there are many isotopes that are much lighter than uranium which are only available by "artificial" means. So, again, there's no unique property that applies only to "man-made" isotopes or transuranic elements.