Answer:
(a) (i) All the elements of a group have similar chemical properties because they have same no. of valence electrons in their outermost shell. (ii) All the elements of a period have different chemical properties because they have different no. of valence electrons in their atoms.
Answer:
390 m
Explanation:
Martha ran 420 m
Cole ran 60 m less than Martha = 420 m - 60 m = 360 m
The distance Kate ran is right in the middle of Martha and Cole's distances
Kate distance = (420 + 360) / 2 = 780 / 2 = 390 m
First, let us calculate the moles of solute or sodium
bicarbonate is in the 1 ml solution.
<span>moles = 1 mL * (1 g
/ 9 mL) = 0.11 moles</span>
The molar mass of sodium bicarbonate is 84 g/mol,
therefore the mass is:
mass = 0.11 moles * 84 g/mol
<span>mass = 9.33 g</span>
Answer:
The correct option is: When the amount of acid and base are equal
Explanation:
Titration is an analytic method that is used to determine the concentration of an<em> unknown solution</em>, called <em>titrand</em>.
In this method, standard solution of known concentration, called <em>titrant</em>, is taken in the burette and added drop-wise to the titrand solution in the flask, until the endpoint is reached.
In case of an acid-base titration, a <em>pH indicator</em> is used, which changes the color of the solution when the endpoint is reached.
<u>The </u><u>endpoint</u><u> indicates the </u><u>equivalence point</u><u> of an acid-base titration, where the </u><em><u>concentration of the acid and base is equal</u></em><u>. </u>
<u>Therefore, the </u><u>correct option</u><u> is: </u><u>When the amount of acid and base are equal</u>
One is ocean
Two is green house effect is the trapping of gas in the atmosphere and global warming is the heating of the earth
Three is option one
