Which of the following scientists first discovered helium in the solar spectrum during a total solar eclipse?

Which of the following is a hypohalous acid?

Which of the following processes involves heating a carbonate ore to form metal oxide?

Which of the following shows the correct sequence of acidic strength?

Why does nitrogen show anomalous properties with respect to other elements in group 15?

From which type of phosphorus is alpha -black phosphorus formed?

How many allotropes does nitrogen have?

Which of the following is the displays the most basic nature in water?