How to remove padding between buttons in android?

Question

Android

Several buttons are sequentially inserted into a LinearLayout. I set the parameter: android:layout_margin="0dp"
But some minimum indent between the buttons still remains. And I want to make the buttons stick together. If you use an ImageButton, then the padding disappears completely, but this does not happen with the Button.

<LinearLayout
        android:orientation="vertical"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_below="@+id/linearLayout"
        android:layout_margin="0dp">

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="25"
            android:id="@+id/button7"
            android:layout_margin="0dp" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="35"
            android:id="@+id/button6"
            android:layout_margin="0dp" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="50"
            android:id="@+id/button8"
            android:layout_margin="0dp" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="80"
            android:id="@+id/button9"
            android:layout_margin="0dp" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="100"
            android:id="@+id/button10"
            android:layout_margin="0dp" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="П1"
            android:id="@+id/button11"
            android:layout_margin="0dp" />
    </LinearLayout>

Answer 1

In general, this problem is background, by default there are no backgrounds in the background, in the shap itself
you need to change the background, read about selectors and create your own
link