2) What advantages do bottles made from plastic have?
3) What disadvantages are there when you use plastic bottles?
4) Why are plastic bowls not used for heating on a cooker?
5) What are the disadvantages of using metal for a toy for a baby?
6) Why is plastic often used for children's toys?
7) What properties would you look for in materials to make a kite?
Answer:
1a) Chemical inertness
1b) transparency
2) extremely less brittle
3) they can melt very easily under moderate heat.
4) they have low melting point
5) metals are hard, meaning they can easily injure a baby. Metals are good absorbers and radiators of heat.
6) they are less hard when compared to metals so they are less probable to cause injuries to kids.
7) material with very low density.
The correct answer is B. Lindsay measures the sizes of the craters on the Moon, is the best description of a person doing science.
Science is the practical and intellectual pursuit of the understanding of the physical and natural world that surrounds us. It involves a systematic study: observation, experimentation, data analysis, discussion and conclusion. Science is the human effort to gather knowledge about the universe.
Answer:
B.
Explanation:
time. It consists of two flasks, one inside the other, that connect at the neck. The space between the two
flasks is completely empty of air.
Q-Why does the design of the vacuum flask minimize heat transfer by conduction?
A)- One flask is smaller than the other flask.
B)- One flask is more reflective than the other flask.
C)- There is no air between the two flasks.
D)- The two flasks do not touch each other, except at the neck.
Answer is: C) There is no air between the two flasks.
Heat in this example can transfer throw thermal conduction.
Because there are no mo molecules to transfer heat, there is no conduction.
Thermal conduction is the transfer of heat through physical contact. Thermal conduction is the transfer of heat by microscopic collisions of particles. Heat spontaneously flows from a hotter to a colder body.
The process of heat conduction depends on four basic factors: the temperature gradient, the cross section of the materials involved, their path length and the properties of those materials.
Because there are no mo molecules to transfer heat, there is no conduction.
Answer:
M(NaOH) = 0.0789 M
Explanation:
NaOH + HCl ---> NaCl + H2O
M(NaOH)*V(NaOH) =M(HCl)*V(HCl)
M(NaOH) *45.0 mL (NaOH) = 0.12 M(HCl) * 29.6 mL(HCl)
M(NaOH) = 0.12*29.6/45.0 = 0.0789 M
neutrons
neutrons and electrons
protons and electrons
Answer : The correct option is, neutrons
Explanation :
Isotope : It is defined as the element that have the same number of protons but have the different number of neutrons of each of the atom.
Atomic number is defined as the number of protons or number of electrons.
Atomic number = number of protons = number of electrons
Mass number is defined as the sum of number of protons and number of neutrons.
Number of neutrons = Mass number - Number of protons
For example : Carbon - 13 isotope has mass number = 13, atomic number = 6 and the number of neutrons = 13 - 6 = 7
Hence, the isotopes of the same element have different numbers of neutrons.