1.写出下列化学符号中所含的数字“2”表示的意义:
1.写出下列化学符号中所含的数字“2”表示的意义:
(1) H2____________________________________
(2) 2H__________________________________
(3) S2-__________________________________
(4) FeSO4_______________________________
2.写出下列意义的符号或符号表示的意义:
(1)7Cu______________
(2)2个氮原子__________________
(3)氯化亚铁中铁元素显+2价____________
(4)2个镁离子_________
(5)3个氢氧根离子___________
(6)硫酸铵_________
(7)硝酸钙_________
(8)碳酸___________
(9)+1价钠元素__________、钠离子_________
(10)+2价锌元素________、锌离子_____________
(11)-1价氯元素_________、氯离子___________
(12)-2价硫酸根_________、硫酸根离子_________
(13)2个铝原子________3个氧分子_________4个硫酸根离子___________铝离子_______
镁元素_____________氯化铜中铜的化合价为+2价_________2个五氧化二磷分子_______
3.写出下列符号中”2”的意义:
(1)2H2O__________________________________
(2)N2_____________________________________
(3)+2MGO_______________________________
(4)2Cl_____________________________________
(5)CO2___________________________________
(6)2FE2+________________________________