Answer:
Mass of CaCl2 that would dissolve is 24.64g.
Explanation:
Explanation is contained in the picture attached.
Answer:
80g=0.08kg
20cm=0.02m
density=m/v
= 0.08/0.02
=4kg/m^3
it is less than density of water so it floats
Chemical properties of matter can only be observed and measured by performing a chemical change.
- Density and boiling are not chemical changes.
- This leaves reactivity and combustion. Reactivity does not need to be observed at STP so the statement is wrong.
Combustion is the best answer.
Answer: option A. the colors absorbed when an element gains energy.
Justification:
The electromagnetic waves, visible light included, consists of a gamma of waves with different frequencies and wavelengths.
The visible light can be decomposed in a set of series of lines of light with different frequencies and that decomposition is what a spectrum of light is. Each series correspond to a color.
The atoms can absorb and emit photons. That is, atoms can absorb and release energy.
When the atom abosorbs a photon an electron gets excited ( the electron gains energy).
The light absorbed, then, corresponds to color absortion, and the spectrum of absortion is the colors absorbed by the atom when its electrons gain energy by the absortion of photons (light).
Answer:
The law of conservation of mass
Explanation:
A chemical equation is an expression of the net composition change associated with a chemical reaction. It shows how a certain amount of reactants yields a certain amount of products. Both of these amounts are measured in moles. Chemical equations often contain information about the state of the reactants: solid, liquid, gas, or aqueous. In addition, they always adhere to the law of conservation of mass, which holds that matter can change form, but cannot be created or destroyed.
