diff --git a/src/lib/expansion/_expansion-theme.scss b/src/lib/expansion/_expansion-theme.scss
index 2ed9552afdc4..0181df45aa90 100644
--- a/src/lib/expansion/_expansion-theme.scss
+++ b/src/lib/expansion/_expansion-theme.scss
@@ -14,10 +14,11 @@
     border-top-color: mat-color($foreground, divider);
   }
 
-  .mat-expansion-panel-header:focus, 
+  .mat-expansion-panel-header:focus,
   .mat-expansion-panel-header:hover {
     background: mat-color($background, hover);
   }
+
   .mat-expansion-panel-header-title {
     color: mat-color($foreground, text);
   }
@@ -29,4 +30,4 @@
   .mat-expansion-indicator::after {
     color: mat-color($foreground, secondary-text);
   }
-}
\ No newline at end of file
+}
diff --git a/src/lib/expansion/accordion-item.ts b/src/lib/expansion/accordion-item.ts
index db2ce5261d54..107f799c2377 100644
--- a/src/lib/expansion/accordion-item.ts
+++ b/src/lib/expansion/accordion-item.ts
@@ -27,15 +27,15 @@ let nextId = 0;
  */
 @Injectable()
 export class AccordionItem implements OnDestroy {
-  /** Event emitted every time the MdAccordianChild is closed. */
+  /** Event emitted every time the MdAccordionChild is closed. */
   @Output() closed = new EventEmitter<void>();
-  /** Event emitted every time the MdAccordianChild is opened. */
+  /** Event emitted every time the MdAccordionChild is opened. */
   @Output() opened = new EventEmitter<void>();
-  /** Event emitted when the MdAccordianChild is destroyed. */
+  /** Event emitted when the MdAccordionChild is destroyed. */
   @Output() destroyed = new EventEmitter<void>();
-  /** The unique MdAccordianChild id. */
+  /** The unique MdAccordionChild id. */
   readonly id = `cdk-accordion-child-${nextId++}`;
-  /** Whether the MdAccordianChild is expanded. */
+  /** Whether the MdAccordionChild is expanded. */
   @Input() get expanded(): boolean { return this._expanded; }
   set expanded(expanded: boolean) {
     // Only emit events and update the internal value if the value changes.
@@ -44,10 +44,10 @@ export class AccordionItem implements OnDestroy {
       if (expanded) {
         this.opened.emit();
         /**
-         * In the unique selection dispatcher, the id parameter is the id of the CdkAccordonItem,
+         * In the unique selection dispatcher, the id parameter is the id of the CdkAccordionItem,
          * the name value is the id of the accordion.
          */
-        let accordionId = this.accordion ? this.accordion.id : this.id;
+        const accordionId = this.accordion ? this.accordion.id : this.id;
         this._expansionDispatcher.notify(this.id, accordionId);
       } else {
         this.closed.emit();
@@ -66,14 +66,14 @@ export class AccordionItem implements OnDestroy {
   constructor(@Optional() public accordion: CdkAccordion,
               private _changeDetectorRef: ChangeDetectorRef,
               protected _expansionDispatcher: UniqueSelectionDispatcher) {
-     this._removeUniqueSelectionListener =
-       _expansionDispatcher.listen((id: string, accordionId: string) => {
-         if (this.accordion && !this.accordion.multi &&
-             this.accordion.id === accordionId && this.id !== id) {
-           this.expanded = false;
-         }
-       });
-    }
+    this._removeUniqueSelectionListener =
+      _expansionDispatcher.listen((id: string, accordionId: string) => {
+        if (this.accordion && !this.accordion.multi &&
+            this.accordion.id === accordionId && this.id !== id) {
+          this.expanded = false;
+        }
+      });
+  }
 
   /** Emits an event for the accordion item being destroyed. */
   ngOnDestroy() {
diff --git a/src/lib/expansion/accordion.spec.ts b/src/lib/expansion/accordion.spec.ts
index 09e198eac768..f29dd5e5ab5e 100644
--- a/src/lib/expansion/accordion.spec.ts
+++ b/src/lib/expansion/accordion.spec.ts
@@ -20,8 +20,8 @@ describe('CdkAccordion', () => {
   }));
 
   it('should ensure only one item is expanded at a time', () => {
-    let fixture = TestBed.createComponent(SetOfItems);
-    let items = fixture.debugElement.queryAll(By.css('.mat-expansion-panel'));
+    const fixture = TestBed.createComponent(SetOfItems);
+    const items = fixture.debugElement.queryAll(By.css('.mat-expansion-panel'));
 
     fixture.componentInstance.firstPanelExpanded = true;
     fixture.detectChanges();
@@ -35,8 +35,8 @@ describe('CdkAccordion', () => {
   });
 
   it('should allow multiple items to be expanded simultaneously', () => {
-    let fixture = TestBed.createComponent(SetOfItems);
-    let panels = fixture.debugElement.queryAll(By.css('.mat-expansion-panel'));
+    const fixture = TestBed.createComponent(SetOfItems);
+    const panels = fixture.debugElement.queryAll(By.css('.mat-expansion-panel'));
 
     fixture.componentInstance.multi = true;
     fixture.componentInstance.firstPanelExpanded = true;
diff --git a/src/lib/expansion/expansion-panel-header.html b/src/lib/expansion/expansion-panel-header.html
index 564a957bf803..4394f4b5742d 100644
--- a/src/lib/expansion/expansion-panel-header.html
+++ b/src/lib/expansion/expansion-panel-header.html
@@ -3,5 +3,5 @@
   <ng-content select="md-panel-description, mat-panel-description"></ng-content>
   <ng-content></ng-content>
 </span>
-<span [@indicatorRotate]="_getExpandedState()" *ngIf="!_getHideToggle()" 
-      class="mat-expansion-indicator"></span>
\ No newline at end of file
+<span [@indicatorRotate]="_getExpandedState()" *ngIf="!_getHideToggle()"
+      class="mat-expansion-indicator"></span>
diff --git a/src/lib/expansion/expansion-panel-header.scss b/src/lib/expansion/expansion-panel-header.scss
index d88885d34396..6a2dab8e9b20 100644
--- a/src/lib/expansion/expansion-panel-header.scss
+++ b/src/lib/expansion/expansion-panel-header.scss
@@ -14,7 +14,7 @@ $mat-expansion-panel-header-height-expanded: 64px;
     line-height: $mat-expansion-panel-header-height-expanded;
   }
 
-  &:focus, 
+  &:focus,
   &:hover {
     outline: none;
   }
@@ -46,7 +46,7 @@ $mat-expansion-panel-header-height-expanded: 64px;
   margin-right: 16px;
 }
 
-/** 
+/**
  * Creates the expansion indicator arrow. Done using ::after rather than having
  * additional nodes in the template.
  */
diff --git a/src/lib/expansion/expansion-panel.html b/src/lib/expansion/expansion-panel.html
index 25422ebc6f70..751e5176a0ab 100644
--- a/src/lib/expansion/expansion-panel.html
+++ b/src/lib/expansion/expansion-panel.html
@@ -5,4 +5,4 @@
     <ng-content></ng-content>
   </div>
   <ng-content select="mat-action-row, md-action-row"></ng-content>
-</div>
\ No newline at end of file
+</div>
diff --git a/src/lib/expansion/expansion-panel.scss b/src/lib/expansion/expansion-panel.scss
index 0a258ad43037..75b188395d48 100644
--- a/src/lib/expansion/expansion-panel.scss
+++ b/src/lib/expansion/expansion-panel.scss
@@ -30,4 +30,4 @@
   button.mat-button {
     margin-left: 8px;
   }
-}
\ No newline at end of file
+}
diff --git a/src/lib/expansion/expansion.spec.ts b/src/lib/expansion/expansion.spec.ts
index abb7495c16e0..160fc96fca73 100644
--- a/src/lib/expansion/expansion.spec.ts
+++ b/src/lib/expansion/expansion.spec.ts
@@ -19,7 +19,7 @@ describe('MdExpansionPanel', () => {
     TestBed.compileComponents();
   }));
 
-  it('should expanded and collapse the panel', () => {
+  it('should expand and collapse the panel', () => {
     const fixture = TestBed.createComponent(PanelWithContent);
     const contentEl = fixture.debugElement.query(By.css('.mat-expansion-panel-content'));
     const headerEl = fixture.debugElement.query(By.css('.mat-expansion-panel-header'));