1.
The group 2A called ?
Correct Answer
D. Alkali Earth metal
Explanation
The correct answer is Alkali Earth metal. Group 2A elements in the periodic table are known as Alkali Earth metals. They include elements such as beryllium, magnesium, calcium, strontium, barium, and radium. These elements have two valence electrons and are highly reactive, although less reactive than the elements in Group 1A (alkali metals). They are generally silver-white in color, soft, and have low melting and boiling points. Alkali Earth metals are important in various industrial applications, such as in the production of steel, aluminum alloys, and fireworks.
2.
Which of the following elements consider metal ?
Correct Answer
A. Na
Explanation
Na (sodium) is considered a metal because it is a solid at room temperature, has a shiny appearance, is malleable and ductile, and conducts electricity. In contrast, C (carbon), N (nitrogen), and He (helium) are non-metals.
3.
The charge of elements in group 8A is :
Correct Answer
D. Zero
Explanation
The charge of elements in group 8A is zero because these elements have a full valence shell of electrons. Group 8A elements, also known as noble gases, have a stable electron configuration with 8 valence electrons (except for helium with 2 valence electrons). As a result, they do not readily gain or lose electrons to form ions, thus having a charge of zero.
4.
Which of the following compounds consider ionic ?
Correct Answer
A. MgS
Explanation
MgS is considered ionic because it is formed by the combination of a metal (Mg) and a non-metal (S). In an ionic compound, electrons are transferred from the metal to the non-metal, resulting in the formation of positive and negative ions. In the case of MgS, magnesium loses two electrons to become Mg2+ ion, while sulfur gains two electrons to become S2- ion. The attraction between these oppositely charged ions holds the compound together, making it ionic.
5.
The correct empirical formula produces from Li and N :
Correct Answer
C. Li3N
Explanation
The correct empirical formula is Li3N because it represents the simplest ratio of atoms in the compound. The subscript 3 next to Li indicates that there are three lithium atoms, while the subscript 1 next to N indicates that there is one nitrogen atom. This ratio of three lithium atoms to one nitrogen atom is the simplest whole-number ratio that represents the composition of the compound.
6.
Which of the following elements consider non-metal ?
Correct Answer
B. Cl
Explanation
Cl (chlorine) is considered a non-metal because it is located on the right side of the periodic table. Non-metals generally have properties such as low melting and boiling points, poor conductivity of heat and electricity, and tend to gain electrons in chemical reactions. Chlorine is a halogen and is known for its strong oxidizing properties. It exists as a gas at room temperature and is highly reactive.
7.
Salt X3P2 , the X ion in this salt has 10 electrons , the metal X is :
Correct Answer
C. Mg
Explanation
The X ion in the salt X3P2 has 10 electrons. This means that the X ion has a charge of 2- since it has gained 2 electrons to reach a stable electron configuration. The only metal in the options that commonly forms a 2- ion is magnesium (Mg). Therefore, the metal X in the salt is magnesium.
8.
The ionic compound from Al and N , Li and S respectively ?
Correct Answer
C. AlN , Li2S
Explanation
The correct answer is AlN and Li2S. AlN is the ionic compound formed between aluminum (Al) and nitrogen (N), while Li2S is the ionic compound formed between lithium (Li) and sulfur (S). In ionic compounds, metals lose electrons to form positive ions (cations), while nonmetals gain electrons to form negative ions (anions). Therefore, AlN is formed by the transfer of one electron from Al to N, resulting in Al3+ and N3- ions. Li2S is formed by the transfer of two electrons from two Li atoms to one S atom, resulting in 2 Li+ ions and S2- ion.
9.
When a metal and non-metal react , the ______ tends to lose electrons and the ______ tends to gain electrins .
Correct Answer
C. Metal , non-metal
Explanation
In a reaction between a metal and a non-metal, the metal tends to lose electrons and the non-metal tends to gain electrons. This is because metals have fewer electrons in their outermost energy level and are more likely to lose them to achieve a stable electron configuration. On the other hand, non-metals have more electrons in their outermost energy level and are more likely to gain electrons to achieve a stable electron configuration. This transfer of electrons from the metal to the non-metal results in the formation of an ionic bond.
10.
Which pair of elements would you expect to exhibit the greatest similarity in their chemical and physical properties ?
Correct Answer
B. O , S
Explanation
Oxygen (O) and sulfur (S) would be expected to exhibit the greatest similarity in their chemical and physical properties. This is because they both belong to the same group in the periodic table, Group 16 (also known as the oxygen group or chalcogens). Elements in the same group tend to have similar properties due to the same number of valence electrons. Oxygen and sulfur both have 6 valence electrons, which means they have similar reactivity and can form similar types of chemical bonds. Additionally, they have similar atomic sizes and electronegativities, which further contributes to their similarity in properties.