Name the element which:(a) is 78% of clean, dry air ........................................................................................................ [1](b) has atoms with an electronic structure of 2,8,1 ................................................................... [1](c) is extracted from hematite ................................................................................................... [1](d) forms an oxide with a giant covalent structure .................................................................... [1](e) is the gas with the slowest rate of diffusion at room temperature

Air is a mixture of gaseous elements and compounds. Which of the following elements makes up the largest proportion of air? A. nitrogen B. water vapor C. carbon dioxide D. oxygen

What is the composition of air ?

Which of the following gases is the most abundant in the air we breathe?Group of answer choicesWater VaporArgonNitrogenOxygen

For each of the following, give the name of an element from Period 2 (lithium to neon), whichmatches the description. Elements may be used once, more than once or not at all. (i) anelement which is gaseous at room temperature and pressure.......................................................................................................................................(ii) an element which forms an oxide that is a reactant in photosynthesis.......................................................................................................................................(iii) an element that is a product of photosynthesis.......................................................................................................................................(iv) an element that makes up approximately 78% by volume of the air.......................................................................................................................................(v) an element which has atoms with a full outer shell of electrons.......................................................................................................................................(vi) an element which exists as both diamond and graphite.......................................................................................................................................(vii) an element that reacts vigorously with cold water.......................................................................................................................................(viii) a soft metallic element which is stored in oil.......................................................................................................................................(b) Give the formula of a compound that contains(i) only boron and oxygen, ................................................................................................(ii) only lithium and nitrogen. ..............

a. Has an atomic number equal to 10b. Has 5 electronsc. Its atomic number is equal to the answer to this mathematical problem: 2 times 5 plus 8divided by 2 minus 8d. A gas that combines easily with a metal to form table salt.e. Belongs to the 3rd energy level family IV Af. A metal that is important to bone formationg. A gas that makes up 21 % of the airh. Has a valence electron of 3s1i. The 1st element in the group VIIIAj. Has 5 valence electrons in the 3rd energy levelk. Belongs to the same group as the element w, named after the place of discoveryl. A metal used in making cooking utensilsm. A yellow crystalline solid nonmetal.n. Has a number of electrons that is one less than the element in Ao. Belongs to the same group as that of the element in h but with a higher energy levelp. Has complete valence electron in period 4q. Has an atomic no. that is twice that of the element in zr. A metalloid that got its name from a countrys. A noble gas with an atomic no. twice that of the element in nt. A nonmetal with a valence of 2s2 2p3u. Has the lowest electronegativity in group IAv. 1st element in group 2Aw. Has an atomic no. that is one less than that of the element in l.x. Has the biggest atomic radius in group VAy. Has 45 neutrons and a mass number of 80z. Has 3 protons