An elements like helium and Boron are formed by stars having a mass of one to eight suns. The example elements that are formed by stars having a mass of one to eight suns are helium and boron. The stars normally turns into a white dwarf when the mass of the stars are less than 5 times the mass of the sun.
Answer:
it says the answer is variation
Explanation:
The most reactive metals are found on the left of the periodic table, in the blue column, known as the alkali metals. Their reactivity increases as we go down column (group) one. Reactive metals, when attached to less reactive metals, have the ability to prevent the less reactive metal from rusting.
Answer: a) 
acid : hydronium ion
base : methoxide ion
conjugate acid : methanol
conjugate base: water
b) 
acid : hydrogen chloride
base : ethoxide ion
conjugate acid : ethanol
conjugate base: chloride ion
c) 
acid : methanol
base : amide ion
conjugate acid : ammonia
conjugate base: methoxide ion
Explanation:
According to the Bronsted-Lowry conjugate acid-base theory, an acid is defined as a substance which looses donates protons and thus forming conjugate base and a base is defined as a substance which accepts protons and thus forming conjugate acid.
The species accepting a proton is considered as a base and after accepting a proton, it forms a conjugate acid.
The species losing a proton is considered as an acid and after loosing a proton, it forms a conjugate base
For the given chemical equation:
a)
acid : hydronium ion
base : methoxide ion
conjugate acid : methanol
conjugate base: water
b)
acid : hydrogen chloride
base : ethoxide ion
conjugate acid : ethanol
conjugate base: chloride ion
c)
acid : methanol
base : amide ion
conjugate acid : ammonia
conjugate base: methoxide ion
.
Let us suppose that we have 1 mol of FeCr2O4. I'm going to use approximate masses because I have no idea what your periodic table will say. Just put in the exact masses from your periodic table.
Fe = 56
Cr*2 = 2*52 = 104
O4 = 4*16 = 64
===========
Total = 56 + 104 + 64 = 224
The % oxygen = (64 / 224) * 100 = 28.5 % but none of your answers match this. Perhaps you are talking about Fe2(Cr2O4)3 The brackets make all the difference in the world.
Without going through all the detail I did before, The molecular mass is
Fe * 2 = 112
Cr * 6 = 312
O * 12 = 192
The total molecular mass = 616
The % Oxygen = (192 / 616) * 100 = 31% roughly. That answer isn't there either.
Let's wait and see who else answers.
