Answer:
Explanation:
The period law state that when elements are listed in order of their atomic numbers, the elements fall into recurring groups, so that there is a recurrence of similar properties at regular intervals.
Na and K in the periodic table fall into the same group, this is because they both have one electrons in their outermost shell.
Na 11 -1s2 2s2 2p6 3s1
K 19 - 1s2 2s2 2p6 3s2 3p6 4s1
They share similar chemical and physical properties. Na and K are very reactive metals, they can loose/donate their outermost electron to non metals in other to attain stable octet state.
The form ionic compound when they react with non metals.
When calcium joins with calcium its follows the following equation:
2Ca + O2 = 2CaO
hope that helps
Answer:
Neils Bohr determined that electrons inhabit distinct energy levels.
Explanation:
Answer:
They are:
Length - meter (m)
Time - second (s)
Amount of substance - mole (mole)
Electric current - ampere (A)
Temperature - kelvin (K)
Luminous intensity - candela (cd)
Mass - kilogram (kg)
Answer:
m = 65.637 g
Explanation:
Heat = 0.612 kJ = 612 J ( Converting to J by multiplying by 1000)
Initial Temperature = 30.°C
Final Temperature = 51°C
Temperature change = Final Temperature - Initial Temperature = 51 - 30 = 21°C
Mass = ?
The relationship between these quantities is given by the equation;
H = mCΔT
where c = 0.444 J/g°C
Inserting the values in the equation;
612 = m * 0.444 * 21
m = 612 / (0.444 * 21)
m = 65.637 g
