Answer:
The order is
Quartz > Calcium > Ammonia > Chlorine
Explanation:
Among given compounds
Quartz is a covalent compound with extensive bondings and thus it will have highest melting point
Calcium is a metal so it will have strong metallic bonds thus will have high melting point, however less than quartz.
ammonia is a polar molecule with weak hydrogen bond as intermolecular interactions thus will have higher melting point than chlorine
chlorine is a non polar molecule with weak intermolecular london dispersion forces.
<span>The answer is letter B. Melting is an endothermic change, because ice absorbs energy from its surroundings as it melts. The melting process absorbs heat energy that causes the ice to melt. Endothermic change is when it absorbs energy from its surrounding. The other choices are incorrect because exothermic change releases energy to its surrounding.</span>
Answer:
1610.7 g is the weigh for 4.64×10²⁴ atoms of Bi
Explanation:
Let's do the required conversions:
1 mol of atoms has 6.02×10²³ atoms
Bi → 1 mol of bismuth weighs 208.98 grams
Let's do the rules of three:
6.02×10²³ atoms are the amount of 1 mol of Bi
4.64×10²⁴ atoms are contained in (4.64×10²⁴ . 1) /6.02×10²³ = 7.71 moles
1 mol of Bi weighs 208.98 g
7.71 moles of Bi must weigh (7.71 . 208.98 ) /1 = 1610.7 g
Answer: Most acids and Alkais are dangerous however not all are dangerous.
Explanation:
