I'm trying to figure out how to get the relativeAtomicMass from one class named ChemicalElement onto another called MolarMass in which I try to figure out the atomicmass of an element given it's symbol then find out a compound mass. I'm not sure how to return a double, I tried using a toString to do it since that's what a tutor taught me to do but I'm not sure if it's the correct way that my teacher wants me to do it. I know I need to get the relativeAtomicMass onto MolarMass to finish the assignment but i'm stuck at the moment. Heres the code for my assignment:
package chemical;
public class ChemicalElement {
// Properties (fields/variables): This time we leave give them default visibility, which gives
// other classes in the same package (i.e. the same directory) full access to them, for brevity.
/** The number of protons */
int atomicNumber;
/** 1-3 letter IUPAC symbol */
String symbol;
/** Full name */
String name;
/** Relative atomic mass () */
double relativeAtomicMass;
/** Row in the periodic table */
int period;
/** Column in the periodic table */
int group;
// Actions (methods): For now we provide a constructor to initialize all fields.
/**
* Constructs a new ChemicalElement object with the given properties.
*
* @param atomicNumber the number of protons
* @param symbol the IUPAC symbol
* @param name the full name
* @param relativeAtomicMass the average atomic mass relative to carbon-12
* @param period the row in the periodic table
* @param group the column in the periodic table
*/
public ChemicalElement(int atomicNumber, String symbol, String name, double relativeAtomicMass,
int period, int group) {
this.atomicNumber = atomicNumber;
this.symbol = symbol;
this.name = name;
this.relativeAtomicMass = relativeAtomicMass;
this.period = period;
this.group = group;
}
public String toString()
{
return name;
}
}
package chemical;
import java.net.URL;
import java.util.Scanner;
import java.util.Arrays;
public class MolarMass {
public static void main(String[] compoundTokens) throws Exception {
ChemicalElement[] elements = readElementData();
//System.out.printf("%.6f%n", compoundmass(elements, compoundTokens));
System.out.println(Arrays.toString(elements));
}
/**
* Loads data about all chemical elements into an array.
*
* @return an array containing references to objects describing all 118 chemical elements
* @throws Exception if anything goes awry (we only know how to pass the buck)
*/
private static ChemicalElement[] readElementData() throws Exception {
ChemicalElement[] elements = new ChemicalElement[119];
Scanner dataFile =
new Scanner(new URL("http://jeff.cis.cabrillo.edu/datasets/elements").openStream());
while (dataFile.hasNext()) {
// Example line: 1 H Hydrogen 1.008 1 1
int atomicNumber = dataFile.nextInt();
elements[atomicNumber] = new ChemicalElement(atomicNumber, dataFile.next(), dataFile.next(),
dataFile.nextDouble(), dataFile.nextInt(), dataFile.nextInt());
}
return elements;
}
/**
* Determines the molar mass of a compound.
*
* @param elements an array containing references to objects describing all 118 chemical elements
* @param tokens a compound formula
* @return the molar mass of the given compound
*/
// private static double compoundMass(ChemicalElement[] elements, String[] tokens) {
// TODO
/**
* Determines the relative atomic mass of an element, given its symbol.
*
* @param elements an array containing references to objects describing all 118 chemical elements
* @param symbol the symbol of the element in question
* @return the relative atomic mass of the given element
*/
// private static double relativeAtomicMass(ChemicalElement[] elements, String symbol) {
// TODO
}
Also i'd imagine that once I get the relative atomic mass onto molarmass it would be easy to fill out the code for relativeatomicmass but how would I use that to create compounds? Thanks any help would be appreciated.
