Answer 1
The sample will dissolve in more than 1 minute.
Explanation :-
Generally Solubility and rate of solubility of substances increase with the increase in temperature. So lower the temperature less fast will it dissolve in the same amount of water.
Since at 50 C it takes 1 minute to dissolve, at 20 C which is lower temperature it will take more time to dissolve.
Answer 2
Transition metals
Explanation:-
Hardness depends on the extent of metallic bonding for metals. More the number of electrons more the metallic bonding.
Alkali metals with just 1 valence electron have weak metallic bonding. Alkaline earth metals have just 2 valence electrons. Transition elements has more electrons in penultimate shell and valence shell than lanthanides. Transition metals with most metallic bonding are the hardest
C metamorphic rock
Why: because o know
Atomic number of carbon = Number of protons = 6
Mass number of carbon = Number of protons + neutrons
= 6 + 5 = 11
Observation is acknowledging and noting some facts from the surroundings or the environment. Usually, observation is done using the five senses of human such as the sense of sight, sense of smell, sense of touch, sense of hearing and sense of tasting. It can also be qualitative and quantitative. Qualitative observations are those who use non-numeric forms in expressing the observation however quantitative uses numeric forms in presenting the observation. Inference on the other hand is the probable explanation or interpretation based on the observation given. Therefore, the statement "The container is filled to the 350 ml mark with water " is an observation.
Increase: volume, pressure, kinetic energy, gas particle collisions
Stays the same: number of moles of gas
