A、二氧化碳是共价化合物,碳原子与氧原子之间形成2对共用电子对,各原子达8电子稳定结构,二氧化碳的电子式为
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/b7fd5266d01609249d7532add70735fae6cd3437?x-bce-process=image/quality,q_85)
,故A错误;
B、氯化钙是离子化合物,由钙离子与氯离子构成,钙离子电子式为Ca
2+,氯离子电子式为
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/0eb30f2442a7d93389b074c5ae4bd11373f0016f?x-bce-process=image/quality,q_85)
,所以氯化钙的电子式为
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/962bd40735fae6cd40e43bd70cb30f2442a70f37?x-bce-process=image/quality,q_85)
,故B正确;
C、氢氧化钠是离子化合物,由钠离子与氢氧根离子构成,钠离子电子式为Na
+,氢氧根离子电子式为
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/43a7d933c895d143ee6e749570f082025aaf076f?x-bce-process=image/quality,q_85)
,所以氢氧化钠的电子式为
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/d833c895d143ad4b9536d67681025aafa40f066f?x-bce-process=image/quality,q_85)
,故C正确;
D、过氧化钠是离子化合物,由钠离子与过氧根离子构成,钠离子电子式为Na
+,过氧根离子电子式为
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/34fae6cd7b899e5132deaaa241a7d933c8950d37?x-bce-process=image/quality,q_85)
,所以过氧化钠的电子式为
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/7a899e510fb30f247dca7cb5cb95d143ad4b0337?x-bce-process=image/quality,q_85)
,故D正确.
故选A.