Answer:
208.7°C was the initial temperature of the limestone.
Explanation:
Heat lost by limestone will be equal to heat gained by the water

Mass of limestone = 
Specific heat capacity of limestone = 
Initial temperature of the limestone = 
Final temperature =
=T = 51.9°C

Mass of water= 
Specific heat capacity of water= 
Initial temperature of the water = 
Final temperature of water =
=T = 51.9°C



On substituting all values:


208.7°C was the initial temperature of the limestone.
Answer:
5.9x10²² atoms of Cu are in one naira coin
Explanation:
To solve this question we need to find the mass of Copper. Then, using its molar mass (Cu = 63.546g/mol) we must find the moles of Cu and its atoms using Avogadro's number:
<em>Mass Cu:</em>
7.3g * 86% = 6.278g is the mass of Cu.
<em>Moles Cu:</em>
6.278g * (1mol / 63.546g) = 0.099moles Cu
<em>Atoms Cu:</em>
0.099moles Cu * (6.022x10²³atoms / 1mol) =
<h3>5.9x10²² atoms of Cu are in one naira coin</h3>
Answer: AIP
There are two types of substances mixture and pure substance. Mixture has NO chemical formula and a pure substance has a chemical formula. There are two types of pure substances, elements (mono atomic and molecular) and compounds ( covalent and ionic).
Ionic compounds do not exist in independent molecular form. They form three dimensional crystal lattice, in which each ion is surrounded by oppositely charged ion. so the ratio of ion is called the formula unit
Answer: a = 2 ; f = 5 ; b = 2 ; g = 2 ; c = 2 ; h = 2 ; d = 4 ; i = 5 ; e = 3 ; j = 7
Explanation: Some rules to follow while calculating sig figs is
1. If a number like 4500 is present, only two sig figs are counted, but none of the zeros are, but if 4500. has a decimal point present, then you should count all the numbers available.
2. If a number like .0005 is present, only count 5 as a sig fig, however if the number is .00050, count the 0 after the 5 in this example (this would then have two sig figs.