Ionic bonds present in the substances: A) Cl₂ B) H₂S C) Ag D) MgO 9. Metallic bonds present in the substances: A) Br₂ B) MgSO₄ C) Au D) BaO
10. Covalent polar bonds bonds present in the substance:
A) H₂ B) BaSO₄ C) Cu D) HF
11. Covalent non polar bonds bonds present in the substances:
A) N₂ B) NaCl C) Cu D) BaO
12. When the periodic system of Mendeleev was discovered?
A) 1882 B) 1904 C) 1869 D) 1774
13. Which of the following is the lightest of the alkali metals?
A) hydrogen B) lithium C) helium D) beryllium
14. Which of the following is a halogen?
A) oxygen B) zinc C) bromine D) hydrogen
15. Which of the following is a noble gas?
A) hydrogen B) iodine C) boron D) neon
16. The sum of all coefficient in the reaction is: Zn + HCl → ZnCl₂ + H₂
A)5 B)3 C)7 D)9
17. The atomic number of the element 3s²3p¹ : A) 12 B) 17 C) 13 D) 14
18. Potassium has the number of energy levels: A) 3 B) 5 C) 1 D) 4
19. The number of neutrons in the atom A) 17 B) 15 C) 16 D) 14
20. What mass of hydrogen gas is produced when 48 g of Mg metal reacts with sulfuric acid solution? Mg+H₂SO₄→MgSO₄+H₂
A) 2g B) 8g C) 6g D) 4g
21. The chemical reaction: 2Ca + O₂ → 2CaO is a:
A) Decomposition B) Сombination C) Single displacement D) Double displacement
22. The chemical reaction BaCl₂ + H₂SO₄ → BaSO₄ + 2HCl is a:
A) Decomposition B) Сombination C) Single displacement D) Double displacement
23. From which group and period atom with 1s² 2s² 2p⁶ 3s²
A) 2A group and 3 period B) 4A group and 3period C) 3A group and 4 period D) 2A group and 4 period
24. 96g of magnesium (Mg) was burned in oxygen gas. Calculate the mass of magnesium oxide formed. 2Mg + O₂ → 2MgO
A) 100g B) 180g C) 160g D) 140g
25. Calculate the relative density of chlorine gas (С