diff --git a/.obsidian/workspace.json b/.obsidian/workspace.json
index ab21d7c..65e8558 100644
--- a/.obsidian/workspace.json
+++ b/.obsidian/workspace.json
@@ -357,6 +357,9 @@
   },
   "active": "e3468b9f6df1ac48",
   "lastOpenFiles": [
+    "empherical formula.md",
+    "chemistry/empherical formula.md",
+    "biology/genetics.md",
     "law of definite proportions and percent composition.md",
     "chemistry/law of definite proportions and percent composition.md",
     "chemistry/polyatomic ions 1.md",
@@ -365,7 +368,6 @@
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     "chemistry/Stoichiometry.md",
     "biology/cell biology.md",
-    "biology/genetics.md",
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     "chemistry/solubility table.md",
     "chemistry/state of matter.md",
@@ -382,8 +384,6 @@
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     "literacy",
     "chemistry/vsepr.md",
-    "math/integrals.md",
-    "math/derivatives.md",
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diff --git a/chemistry/empherical formula.md b/chemistry/empherical formula.md
new file mode 100644
index 0000000..72d4ef5
--- /dev/null
+++ b/chemistry/empherical formula.md	
@@ -0,0 +1,5 @@
+[[Stoichiometry]]
+
+empirical formulas are the simplest whole number ratio of atom in a substance
+
+eg acetic acid and glucose share an empherical of ch_2o
\ No newline at end of file