Answer:
The result is 3.859 in which we use four significant figures.
Explanation:
We start by solving the mathematical operation :
The result for the operation is 3.859438 but the numbers in the operation are given with four significant figures and that is why we are going to use four significant figures to express the result
To express 3.859438 with four significant figures we use the first four digits that appear from left to right starting by the first digit that is different to zero
In this case : 3.859 will be the result with four significant figures.
We also use a rule that says : To decide if the last significant figure remains the same we look for the value of the digit at its right.
If that number is greater than or equal to 5 ⇒ we sum one to the last significant figure
For example 3.859738 = 3.860 with four significant figures because the ''7'' is greater that 5
If that number is less than 5 ⇒ the last significant figure remains the same
In our case : 3.859438 = 3.859 because ''4'' is less than ''5''
Answer:
B. CH₄
Explanation:
The primary rule in deciding solubilities is, Like dissolves like. That is,
- A polar solute dissolves in a polar solvent.
- A nonpolar solute dissolves in a nonpolar solvent.
C₆H₁₄ is a nonpolar solvent. Its strongest intermolecular forces are London dispersion forces.
CH₄ is a nonpolar solute. It contains only nonpolar C-H bonds, and its strongest intermolecular forces are London dispersion forces.
Molecules of the two compounds can easily intermingle with each other because the attractive forces between them are so small.
A is wrong. H₂O is a highly polar substance. Its molecules are so strongly attracted to each other that they will not dissolve in the C₆H₁₄.
C and D are wrong. Both NaCl and SnS are compounds of a metal and a nonmetal. We would predict them to be ionic solids, at the extreme end of polarity. They will not dissolve in C₆H₁₄.
Iodine is a group 7A element. The halogens form anions because of their high electronegativities, so Iodine is unlikely to form a cation.
Answer: Hydrogen belongs to group 1 metal elements in the periodic table.
Explanation:
The hydrogen is a highly active metal. It has a single electron in its valence shell and it can donate its electron to other metal atoms. Thus forming metal hydrides. The hydrogen when ignited it reacts with oxygen and burns explosively this is indicative of high reactivity and spontaneous reactivity of hydrogen atom.
Answer: A. is prey B. is predator C. is habitat D. is comunity E. is plants are producers and plant eating animals consumors F. is food chain G. is food web H. parasite I decomposers and scavengers J. is compete K an adsption
Explanation:
