Is burning of maganisums exothermic or endothermic reaction

Which of the following can be used to measure electricity

To apply in a gold the individual gold atoms are united to each other by means of a metallic bond. how would you use the gold block to determine the atomic radius of a gold atom?

Covalent bonds generally form when the bonded elements have a difference in electronegativity less than 1.5. subtract the electronegativities for the following pairs of elements and predict whether they form a covalent bond. electronegativity difference of c and c: ionic covalent electronegativity difference of mg and cl: ionic covalent