please help me with these chemistry problems!

问题描述:

please help me with these chemistry problems!
1.When a substance freezes,it changes from the liquid phase to the solid phase because of its _____.
1.molecular bonding
2.ntermolecular bonding
3.compactness
4.ability to fit the shape of its container
2.The elements in group 2 all have _____ valence electrons.
3.An ongoing series of fission reactions is called a (n) _____.
4.A sample of sulfur has a mass of 232 grams.How many moles of sulfur are in the sample?
5.A molecule that does not have a positive end and a negative end is called a _____ molecule.
6.Lithium,a group 1 element with an electron configuration of 1s22s1,will form a _____ ion in a chemical reaction.
7.Given the following balanced reaction between nitrogen gas and oxygen gas to produce nitrous oxide gas,how many moles of nitrous oxide gas are produced from 1.65 moles of nitrogen gas?
N2(g)+o2(g) ------2NO(g)
8.A (colloid/suspension/solution) is a heterogeneous mixture in which the particles settle to the bottom.
9.Predict which atom has the higher ionization energy?Mg or Na?
10.Copper and silver are two examples of atoms that will form a(n) _____.(covalent or ionic bond?)
11.Calculate the density of a piece of bone with a mass of 3.8 grams and a volume of 2.0 cubic centimeters.
12.What is the molar mass of oxygen,O2?(Round to four significant figures only.)
1个回答 分类:英语 2014-09-26

问题解答:

我来补答
1.2
2.lone
3.nuclear fission
4.232/32
5.unpolar
6.positive
7.0.55
8.suspension
9.Mg
10.ionic
11.(3.8/M(CaCl2))/2.0
12.自己查
看在偶也蛮辛苦的份上,给分吧
 
 
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