Science

science

Q1-According to which property are the elements in the modern periodic table 

Organized left to right? 

• Reactivity 

• Relative atomic mass 

• Melting point 

• Atomic number 

• Density 

✅ Atomic number - Elements are arranged from the smallest atomic number to the largest (e.g. Hydrogen = 1, Helium = 2, Lithium = 3). 

Q2-Which of the following best describes a period in the periodic table? 

• A collection of elements in a single column  

• A collection of elements in a single diagonal  

• All elements with a specific number of neutrons in their nuclei 

• All nonmetals 

• A collection of elements in a single row  

✅ Answer: A collection of elements in a single row. 

Q4-What do elements in the same group of the periodic table contain an equal number of? 

• Valence electrons 

• Electrons  

• Valence electron orbitals  

• Valence electron shells 

• Electron shells 

✅ Answer: Valence electrons 

Q5-which atomic feature do elements in the same period of the periodic table contain an equal number of? 

• Electron shells 

• Neutrons  

• Electrons  

• Protons  

• Electron orbitals  

✅ Answer: Electron shells

Q8-phosphorus is in group 15 of the periodic table how many covalent bonds does an atom of phosphorus usually form? 

✅ Correct answer: 3 covalent bonds 

Q9-Given the equation below, which one of the following groups could X be in? 

2X+3C12-X2C16 

• Group 15 

• Group 13 

• Group 17 

• Group 2 

✅ Correct answer: Group 13 

Q10-What is the shell number of the valence shell in a chlorine atom? 

✅ Answer: 3 

Q11-For which of the following elements in the second electron shell the valence shell? 

• Hydrogen 

• Helium  

• Carbon 

• Aluminium 

• Chlorine  

✅ Correct answer: Carbon 

Q12-Which of the following is an alkaline earth metal? 

• Scandium 

• Rubidium 

• Strontium  

• Lithium 

• Yttrium  

✅ Correct answer: Strontium 

Q13-oxygen commonly forms two covalent bonds. In which group of the periodic table is oxygen located? 

• Group 16 

• Group 6 

• Group 4 

• Group 2 

• Group 18 

✅ Correct answer: Group 16 

Q14-for the given reaction, which of the following elements could be represented by X? 

X+2C12-XC14 

• Silicon  

• Calcium  

• Indium 

• Rubidium  

✅ Correct answer: Silicon 

Q15-in which period of the periodic table is the fourth electron shell of an atom the valence shell? 

✅ Correct answer: Period 4 

Q17-Fill in the blank. For the given reaction, element X is a ...? element. 

X+2h2O-X(OH)2+H2 

• Group 2 

• Group 15 

• Group 17 

• Group 1 

✅ Correct answer: Group 2 

Q18-Aluminum is in group 13. How many electrons are there in the valence shell of an aluminum atom? 

✅ Correct answer: 3 electrons 

Q20-How many occupied electron shells are present in a hydrogen atom? 

✅ Correct answer: 1 

Q21-an unknown element forms an ion with a charge of 2+. In which group of the periodic table is this element most likely to be located? 

• Group 1 

• Group 18 

• Group 0 

• Group 2 

• Group 7 

✅ Correct answer: Group 2 

Q22-Sulfur is on group 16, what is the charge of the sulfide anion? 

✅ Correct answer: 2− 

Q23-For the following reaction, which of the given elements would X most likely represent? 

2X+F2-2XF 

• Potassium  

• Strontium  

• Magnesium  

• Gallium  

✅ Correct answer: Potassium 

Q24-which of the following is not an alkaline earth metal? 

• Beryllium  

• Lithium 

• Calcium  

• Magnesium 

• Radium 

✅ Correct answer: Lithium 

Q25-which of the following in not an alkali metal? 

• Potassium  

• Calcium  

• Sodium  

• Cesium 

• Lithium. 

✅ Answer: Calcium