Remember....
mass number= atomic number + number of neutrons
If the mass number is 19 and the atomic number is 9, then the number of neutrons is 19-9 which is 10.
Answer:
By sharing their valence electrons, both hydrogen atoms now have two electrons in their respective valence shells. Because each valence shell is now filled, this arrangement is more stable than when the two atoms are separate.
Explanation:
Answer:
The correct option is B
Explanation:
The number of valence electron(s) increases across the period and thus influences the direction of periodic trend of electronegativity, electron affinity and ionization energy across the period. Thus, making option B the answer.
It should be noted that option A is wrong because elements in the same period generally have the same number of electron shells and thus the distance of this shells from the nucleus remains the same throughout the same period and thus option C is also wrong. Option D is wrong because the periodic trends have to do with chemical reactions which actually involves electrons and not protons.
Answer:
A) IV: number of hours DV: score
Explanation:
Coz,
IV- is the variable that u change
DV- is the variable that u test or measure
In this case, we need to change the hours of studying to see how studying for different hours [1 hr, 2hr, etc (( Independant variable coz we're changing the no. of hours)) ] is going to affect the student's score, and in the end, we are measuring the score of each student [this is the dependant variable].