Answer:
3.052 × 10^24 particles
Explanation:
To get the number of particles (nA) in a substance, we multiply the number of moles of the substance by Avogadro's number (6.02 × 10^23)
The mass of Li2O given in this question is as follows: 151grams.
To convert this mass value to moles, we use;
moles = mass/molar mass
Molar mass of Li2O = 6.9(2) + 16
= 13.8 + 16
= 29.8g/mol
Mole = 151/29.8g
mole = 5.07moles
number of particles (nA) of Li2O = 5.07 × 6.02 × 10^23
= 30.52 × 10^23
= 3.052 × 10^24 particles.
Answer:
Explanation:
Group 4A contains a total of 4 electrons for each atom in their valence shell. Filling the orbital diagram, let's say, for carbon, notice that when we start with period 2, we have two elements in the s-block, that is, lithium and beryllium. They correspond to the two s electrons that belong to the valence shell of carbon.
Moving on, we have boron and carbon, the remaining 2 electrons. Now, starting with boron, we're in the p-block.
That said, looking at the second period, the electron configuration for the valence shell of a group 4A element would be:
30% should be the percentage of oxygen if the total mass of fe2o3 is 160.
Answer:
B
Explanation:
Because when a cold object is cold it start to get warm because Of the air.
and it start to warm and it gets warm.
The number of particles (molecules, atoms, compounds, etc.) per mole of a substances is known as Avagadro number. It is equal to 6.022×10^23 mol-1 and is expressed as NA.
Number of moles is the amount of a substance that contains as many particles as there are atoms in 12 grams of pure carbon-12. So, 1 mol contains 6.022×10^23 elementary entities of the substance. Since 6.022 x 10^23 is the Avagadro number, one mole is equal to Avagadro number.
One mole of a substance is the ratio of mass of the substance by the molecular mass of the substance. Thus the mass of one mole of a substance is equal to the substance's molecular weight. Thus one mole of a substance is the atomic mass unit of a substance and since one mole is equivalent to the Avagadro number,we can conclude that one Avagadro number is one atomic mass unit of the substance.
