Chủ đề:

Bài 2: Axit - Bazơ - Muối

Câu hỏi:

Cho các chất sau: Al(OH)₃, Fe(OH)₃, Mg(OH)₂, Zn(OH)₂, Ba(OH)₂, NaOH. Số hiđroxit lưỡng tính là

A

4.

B

2.

C

1.

D

3.

Chủ đề:

Chương 1. Nguyên tử

Câu hỏi:

Tổng số hạt nguyên tử là 58 . Số hạt mang điện nhiều hơn số hạt không mang điện là 18 hạt . Xác định Z, N , E , A

Chủ đề:

TEST 1

Câu hỏi:

Be more careful or you’ll cut your finger. => If________ * Study harder or you’ll fail the test=> If_____________ * Recycle things or we will damage our environment. =>If __________ * Nobody can do this math because it is so difficult. => Because of ____________ * It rains heavily so we can’t go for a walk. => Because of__________ * The rice plants will die because the rice paddies are polluted. => Because of_________________________ * Tim can’t buy this house because he doesn’t have enough money. => Tim can’t buy this house because of_________ * Water the flowers or they will die. =>If_______ * If we go on littering, our environment will become seriously polluted. => Unless________ * She is tired. She stayed up late doing her homework.=> As_______ *