Intent não abre browser

Boa noite. Fiz conforme vídeo aula porem não abre o browser.

package com.example.marce.agenda;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.provider.Browser;
import android.provider.Settings;
import android.support.v7.app.AppCompatActivity;
import android.view.ContextMenu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;

import com.example.marce.agenda.dao.AlunoDAO;

import java.util.List;

public class ListaAlunosActivity extends AppCompatActivity {

    private ListView listaAlunos;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_lista_alunos);

        listaAlunos = (ListView) findViewById(R.id.listaAlunos);

        listaAlunos.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> lista, View item, int position, long id) {
                Aluno aluno = (Aluno) listaAlunos.getItemAtPosition(position);

                Intent intent = new Intent(ListaAlunosActivity.this, FormularioActivity.class);
                intent.putExtra("aluno",aluno);
                startActivity(intent);

                Toast.makeText(ListaAlunosActivity.this, "Aluno = " + aluno.getNome(), Toast.LENGTH_SHORT).show();
            }
        });

        listaAlunos.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
                Toast.makeText(ListaAlunosActivity.this, "Clique longo", Toast.LENGTH_SHORT).show();
                //se colocar true ele executa tb o onCreateContextMenu
                return false;
            }
        });

        Button novoAluno = (Button) findViewById(R.id.novo_aluno);

        novoAluno.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(ListaAlunosActivity.this, FormularioActivity.class);

                startActivity(intent);
            }
        });

        registerForContextMenu(listaAlunos);

    }

    @Override
    protected void onResume() {
        super.onResume();
        carregaLista();
    }

    private void carregaLista() {
        AlunoDAO dao = new AlunoDAO(this);
        List<Aluno> alunos = dao.buscaAlunos();
        dao.close();

        ArrayAdapter<Aluno> adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, alunos);
        listaAlunos.setAdapter(adapter);
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, final ContextMenu.ContextMenuInfo menuInfo) {

        MenuItem itemSite = menu.add("Visitar Site");
        Intent intentSite = new Intent(Intent.ACTION_VIEW);
        intentSite.setData(Uri.parse("https://www.google.com.br"));
        intentSite.setAction(Settings.ACTION_IGNORE_BATTERY_OPTIMIZATION_SETTINGS);
        itemSite.setIntent(intentSite);

        MenuItem deletar = menu.add("Deletar");
        deletar.setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener() {
            @Override
            public boolean onMenuItemClick(MenuItem item) {
                AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) menuInfo;
                Aluno aluno = (Aluno) listaAlunos.getItemAtPosition(info.position);

                AlunoDAO dao = new AlunoDAO(ListaAlunosActivity.this);
                dao.deleta(aluno);
                dao.close();
                carregaLista();

                Toast.makeText(ListaAlunosActivity.this, "Item clicado = " + aluno.getNome(), Toast.LENGTH_SHORT).show();
                return false;
            }
        });


    }

}