She wants to study gynaecology but that may require her to take off the niqab sometimes
Question

                I am a 16 year old muslim girl who lives in the U.K. I am in year 11 and finishing secondary school in a couple of weeks.

I am of the opinion that covering the face and hands is obligatory. I want to go to sixth form but only a minority are not mixed . So I am trying to find some schools that have an an all girls sixth form or more females than males in the school. In order to reduce and prevent free-mixing as much as possibble. As, I have seen the evil consequences of free mixing(in regards to others not personally me) ; my secondary school is a mixed school. At the time I wanted to leave my parents didnt allow me.
I would be dissallowed to wear the niqab to secondary school so I wear it outside of school.

I fear that these few sixth forms and colleges that accepted me wearing niqab, may want me to remove my niqab and gloves during science practical lessons. Such as, when things are being heated or burnt due to health and safety reasons. Also when I am sitting exams for identification purposes.

Am I allowed to comprimise and remove my niqab during these practicals? Or even when I inshaAllah go to medical school to become a gyneacologist/obetrician. I think the niqab will not be permitted. So am I sinworthy if I take my niqab off whilst in the school? Even though males will be around? Or am I permitted because I want a career path that can benefit muslims and women in particular?
Praise be to Allah.
    Firstly: 

    Mixing of men and women in education, work 
    or otherwise leads to serious consequences and many evils, and the harmful 
    outcomes have become very clear and cannot be denied. Shaykh al-Islam ibn 
    Taymiyah (may Allah have mercy on him) said: 

    If men mix with women, it is like fire 
    mixing with wood. End quote from al-Istiqaamah (1/361) 

    For more information, please see the 
    answer to question no. 
    1200. 

    Hence what you must do is look for a place 
    where there is no mixing between men and women. 

    Secondly: 

    Covering the face and hands for women is a 
    matter concerning which there is a difference of scholarly opinion. The most 
    correct view is that on which fatwas on this website are based, which is 
    that it is obligatory to cover them because of the evidence which has been 
    explained in detail in fatwa no. 
    11774. 

    Thirdly: 

    It is known that knowledge of medicine is 
    a communal obligation, especially with regard to women learning gynaecology 
    and obstetrics, so that there will be sufficient female Muslim doctors, 
    which will spare women the problem of having to uncover their ‘awrahs in 
    front of male doctors. The basic principle is that a woman is encouraged to 
    study medicine in a proper environment that is controlled by Islamic 
    guidelines. But if you have no opportunity to study medicine except by 
    uncovering your face and hands on occasion, then there is no blame on you 
    for that, especially since the obligation of covering the face and hands is 
    a matter concerning which the scholars differed. The scholars have stated 
    that concessions are allowed in the case of a woman studying medicine 
    regarding matters that are more serious than that, such as uncovering 
    ‘awrahs, touching them, and so on. This has been explained previously in 
    fatwa no. 
    169979

    But you must hasten to cover up again once 
    the need has passed, and strive hard to avoid occasions of mixing and 
    interacting with those with whom you are not obliged to interact and mix. 

    And Allah knows best.