An atoms consists of protons, electrons and neutrons. Protons are positively charged while electrons are negatively charged. Both are electrically attracted to each other. Meanwhile, the neutrons are electrically neutral which do not have a charge. This means that neutrons are neither electrically attracted to the protons nor electrons,
First row: HCl, ZnCl2, FeCl3, AlCl3, BaCl2, PbCl4
Second row: H3P, Zn3P2, FeP, AlP, Ba3P2, Pb3P4
Third row: HNO3, Zn(NO3)2, Fe(NO3)3, Al(NO3)3, Ba(NO3)2, Pb(NO3)4
Fourth row: ZnO, Fe2O3, Al2O3, BaO, PbO2
Fifth row: HCaF2, Zn(CaF2)2, Fe(CaF2)3, Al(CaF2)3, Ba(CaF2)2, Pb(CaF2)4
Sixth row: H2SO4, ZnSO4, Fe2(SO4)3, Al2(SO4)3, BaSO4, Pb(SO4)2
Answer:
All of the given statements are true.
Explanation:
All the elements are heavier than Bismuth (Bi) are radioactive.
The time for half of the original sample to spontaneous decay is called half life (
)

All radioactive elements are spontaneously decaying towards formation of a stable element.
Radioactive elements undergo decay in order to attain stability.
Radioactivity is a natural part of our environment. The earth also contains several primordial long-lived radioisotopes that have survived to the present in significant amounts.
Hence, all the given statements are true.
Answer:
Strontium
Explanation:
In the periodic table, an element with two (2) valence electrons is found on group 2. Group 2 is a group of the periodic table that harbors element called ALKALINE EARTH METALS. As the name implies, they are metals that possess shiny and solid characteristics at room temperature.
Group 2 elements include the following: Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), barium (Ba), and radium (Ra). Based on the descriptive information in this question, the element being described is a GROUP 2 element. Based on the elements in the option, only STRONTIUM (Sr) is a group 2 element.