Top answers


what forces hold the ions together in an ionic compound?

electrostatic forces between oppositely charged ions.
AJ
Answered by Anushka J. • Chemistry tutor
9078 Views

How does vaccination confer immunity to a person?

The dead or inactive form of the pathogen stimulates the adaptive immune system. It forces white blood cells to form antibodies against the pathogen, so that if a future invasion by the same pathogen was to ...
AJ
Answered by Anushka J. • Biology tutor
3114 Views

Q4: Some small organisms do not have a specialised gas exchange system like humans. Instead they absorb oxygen through their skin. What is this process called? • Transpiration • Respiration • Diffusion • Photosynthesis

The answer is Diffusion. This is random movement of a substance from an area of high concentration (the air) to a region of low concentration (inside the organism). In this case, the substance diffusing woul...
RT
Answered by Rebecca T. • Biology tutor
4045 Views

Describe the structure of metal and its bonding and how its structure contribute to its properties.

Metals have a distinct bonding known as metallic bonds, where there is a sea of delocalised electrons and metal ions present. This is due to electrons leaving the atom forming a positive metal ion and a sea ...
AP
Answered by Ann P. • Chemistry tutor
9092 Views

Expand and and simplify (x^2 + 7) (x - 1)

Firstly, it is important to understand here that "expand" means multiply the two brackets. A logical approach can be taken to this question. Deal with the first term (x^2) of the first bracket: mul...
ST
Answered by Sherin T. • Maths tutor
4397 Views