Answer:
Answer: (b) F
Explanation:
Sodium has 1, magnesium has 2 and Aluminium has 3 electrons in its outermost shell whereas Fluorine has 7 electrons in its outermost shell hence Fluorine does not lose electrons easily.
The electronic configuration of fluorine is 2,7.
Fluorine is the ninth element with a total of 9 electrons.
The first two electrons will go in the 1s orbital.
The next 2 electrons for F go in the 2s orbital.
The remaining five electrons will go in the 2p orbital. Therefore the F electron configuration will be 1s22s22p5.
The right option is; b. mechanical
Mechanical energy is the best description of the energy of the ball as it flies over the pitcher’s head.
Mechanical energy is the energy that an object acquires due to its position or due to its motion. From the question, the baseball player has chemical potential energy (stored as food) which is transformed into work. As the baseball player hits the ball, there is energy exchange in which the ball acquires energy to perform its work. The energy obtained by the ball upon which work is done is called mechanical energy.
Answer: a. two substances present; two phases present : Heterogeneous mixture
b. two substances present; one phase present
: Homogeneous mixture
c. one substance present; one phase present
: pure substance.
d. one substance present; two phases present: Heterogeneous mixture
Explanation:
A pure substance is a substance which contains definite composition of only one type of component. Hence, it cannot be separated by physical means.
Mixture is a substance which contains two or more than two types of components and they can be separated by physical means as well.
Homogeneous mixtures: It is a mixture that has uniform composition throughout the solution and the particle size or shapes are not different. There is no physical boundary between the dispersed phase and dispersion medium.
Heterogeneous mixtures: It is a mixture that has non-uniform composition throughout the solution and the particle size or shapes are also different. There is a physical boundary between the dispersed phase and dispersion medium.
The balanced chemical reaction is written as :
Na2CO3<span> + 2HCl === 2NaCl + H2O + CO2
</span>
We are given the amount of NaCl to be produced from the reaction. This will be the starting point for the calculations. We do as follows:
120 g NaCl ( 1 mol / 58.44 g) ( 1 mol Na2CO3 / 2 mol NaCl)( 105.99 g / 1 mol ) = 1108.82 g Na2CO3 needed
