Answer: 1.90x10²³ atoms of O
Explanation: First convert the mass of O into moles:
5.06 g O x 1 mole O / 16 g O
= 0.32 moles O
Next use Avogadro's Number to find the number of atoms of O
0.32 moles O x 6.022x10²³ atoms O / 1 mole O
= 1.90x10²³ atoms O
Answer:
102
Explanation:
(20+1+30)*2
you add the total number of atoms that can be found in one molecule of vitamin A then multiply by 2
Answer: The volcanic eruptions started and the comet or asteroid that was a fatal hit had a run-in with the dinosaurs.
Answer:
number of moles of the compound 
53 mole
Explanation:
Given that:
The total energy liberated = - 2870 kJ ( here , the negative sign typical implies the release of energy due to the combustion reaction)
The equation of the reaction can be represented as:
The energy needed to synthesize 1 mole of compound X = - 54.1 kJ.mol
Thus;
The total energy = numbers of moles of compound × Energy needed to synthesize 1 mole of compound X
Making the numbers of moles of the compound the subject; we have;
numbers of moles of compound = 
number of moles of the compound = 53.04990 mole
number of moles of the compound 53 mole to two significant figure
Answer:
To predict what triggers cell-to-cell communication
Explanation:
Methodologies used for studying cell-to-cell communication includes
1) The reductionist method in which cellular response are measured based on testing specific cellular signals by the introduction of different chemicals, so as to find the source that triggers the response
2) By the application of known chemical reagents enable or block specific areas of an organism's receptors and with the aid of an electrode measure the cellular response based on generated currents of ions or by collecting and analyzing fluid samples from the affected area.
