She must have used the torch as Sun, the tennis ball as Earth and the marble as Moon.
Answer:
1.38×10^25 molecules
Explanation:
Applying n= (no. of molcules)/NA
23 = N/6.02×10^23
= 1.38×10^25 molecules
1 kilo joule = 0.239006 calories
134 kilo joule = 134 x 0.239006
= 32.026804 calories
Answer:
a. Be and Mg
Explanation:
Be (beryllium) and Mg (magnesium) are both found in the alkaline earth metals family (group 2) on the periodic table. Elements in the same family or group have similar properties,
Ca and Br are in groups 2 and 17
Cl and Ar are in groups 17 and 18
Na and P are in groups 1 and 15
What are the answers choices?