Question

1. the following table shows the mohs hardness scale. it uses talc at 1 as the softest and diamond at 10 as the hardest. the list beside the table shows the mohs numbering of some common objects. scientists use this information to find out what a mineral is. for example, if a copper penny can scratch it, but a fingernail cannot, it might be gypsum. mohs hardness scale mineral scale talc (softest) 1 gypsum 2 calcite 3 fluorite 4 apatite 5 feldspar 6 quartz 7 topaz 8 corundum 9 diamond (hardest) 10 hardness of common objects • fingernail 2.5 • copper penny 3.5 • iron nail 4.5 • glass 5.5 • steel - nail 6.5 you are studying samples of the 10 minerals listed in the mohs scale of hardness. use the scale and the list of common objects to fill in the following chart. 3. what happens in a chemical reaction? a solids always become a gas. b matter is created. c new substances are formed. d atoms change to protons.

Explanation:

En una reacción química, los reactivos se combinan o se descomponen para formar nuevos productos, lo que significa que se forman nuevas sustancias. Las opciones A y B son incorrectas porque no siempre los sólidos se convierten en gas y la materia no se crea ni se destruye (ley de conservación de la materia). La opción D es incorrecta porque los átomos no cambian a protones en una reacción química.

Answer:

C. New substances are formed.