Question

Which statement describes both homogeneous mixtures and heterogeneous mixtures?

Answer 1

Answer :

(1) The correct option is, Their components can be separated by physical processes.

(2) In the given image, image 1, 2 and 4 belong to the same element.

(3) The correct option is, kelvin

Explanation :

For 1 :

Heterogeneous mixtures : It is a mixture that appears non-uniformly throughout the solution and the particle size or shapes are also different.

Homogeneous mixtures : It is a mixture that appears uniformly throughout the solution and the particle size or shapes are not different.

The similarity between the homogeneous and heterogeneous mixture is that their components can be separated by physical processes. As the mixture of salt and water is homogeneous mixture which can be separated by the evaporation and the mixture of sand and water is heterogeneous mixture which can be separated by the filtration. Evaporation and filtration is a physical processes.

For 2 :

The element having the same number of protons are called as isotopes of the same element.

From the image given, three of the structures justify the above statement.

The three atomic models are model 1, model 2 and model 4.

For 3 :

S.I : It is defined as a scientific method to express the magnitude of the several basics units.

There are seven basic units in the system from which the other units are derived.  The seven base unit are, meter for length, kilogram for mass, second for time, ampere for current, kelvin for temperature, mole for amount of substance and candela for intensity.

As we know that the temperature can be measured in, degree Celsius, degree Fahrenheit and kelvin.

Thus, the SI unit of temperature is, kelvin

Answer 2

1) Answer is: C.  Their components can be separated by physical processes.

Mixtures can be separeted physically, while compounds cannot.

For example if we have mixture of water and alcohol ethanol, we can separate water and ethanol with distillation (process of heating and cooling). Ethanol and water have different boiling points (physical property).

But if we want to separate water (compound) into oxygen and hydrogen, we must brake bonds between oxygen and hydrogen and that is not physical property.

2) Answer is: the atomic models with two protons (red balls with P).

The atomic number (Z) determines total number of protons and uniquely identifies a chemical element, also the atomic number is equal to the number of electrons in neutral atom.

This element (helium He) has two protons and two electrons, number of neutrons (yellow balls with N) is different.

3) Answer is: A. degree Celsius.

The Celsius scale, also known as the centigrade scale, is a temperature scale used by the International System of Units (SI).

The Celsius scale was based on 0°C for the freezing point of water and 100°C for the boiling point of water at 1 atm pressure.

The temperature T in degrees Celsius (°C) is equal to the temperature T in Kelvin (K) minus 273,15: T(°C) = T(K) - 273.15.