Method
Preheat the oven to 350 degrees F (175 degrees C). Grease one 10-inch tube pan.
Sift flour, baking soda, and salt together in a medium bowl. Set mixture aside.
In a large bowl, beat egg whites until soft peaks form. Gradually add 1/2 cup sugar, beating until stiff glossy peaks form. Set aside.
Beat butter and remaining 1 1/2 cups sugar in another large bowl with an electric mixer until fluffy, 3 to 5 minutes. The mixture should be noticeably lighter in color.
Blend in egg yolks, lemon zest, and lemon juice. Add flour mixture alternately with yogurt, mixing until combined. Gently fold in beaten egg whites and pour batter into the prepared pan.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, 50 to 60 minutes. Let cake cool in the pan for 10 minutes, then turn out onto a wire rack to finish cooling.
If you use Greek-style yogurt, you may thin it with a little milk to make it easier to incorporate into the batter.