Answer:
1. Previous Eye Surgery
.
Explanation:
1.
Your medical history can also affect your vulnerability to cataracts. For instance, a previous eye surgery can cause secondary cataracts. Other conditions including diabetes and excessive use of steroids accelerate the chances of cataracts once a person has already undergone previous eye surgeries.
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.
Answer:
The energy difference between these 2p and 2s orbitals is 
Explanation:
Wavelength of the photon emitted = 
Energy of the photon will corresponds to the energy difference between 2p and 2s orbital = E
Energy of the photon is given by Planck's equation:

h = Planck's constant = 
c = Speed of the light = 


The energy difference between these 2p and 2s orbitals is 
Answer:
1. c) shiny
2) True. Reactivity is a chemical property.