1.
His experiments on beryllium and alpha particles showed the existence of the third subatomic particle, the neutron, which is uncharged and located in the nucleus.
Correct Answer
B. James Chadwick
Explanation
James Chadwick is the correct answer because his experiments on beryllium and alpha particles led to the discovery of the neutron, a subatomic particle that is uncharged and located in the nucleus. This discovery was significant in advancing our understanding of atomic structure and the composition of matter.
2.
It is formed when electrons are removed or added to a neutral atom.
Correct Answer
D. Ions
Explanation
Ions are formed when electrons are removed or added to a neutral atom. This process results in the atom becoming positively or negatively charged. Isotopes are atoms of the same element with different numbers of neutrons, while cations are positively charged ions. Nuclide refers to a specific atomic nucleus with a particular number of protons and neutrons. Therefore, the correct answer is ions.
3.
How to find the Charge of an Ion?
Correct Answer
A. No. of protons – no. of electrons
Explanation
The charge of an ion is determined by the difference between the number of protons and the number of electrons. If there are more protons than electrons, the ion will have a positive charge. If there are more electrons than protons, the ion will have a negative charge. Therefore, the correct answer is "no. of protons - no. of electrons".
4.
He performed experiments using his positive ray tube containing tubes with different gases at very low pressures with perforated tube and concluded that the positively charged particle in the atom is called proton.
Correct Answer
C. Eugene Goldstein
Explanation
Eugene Goldstein performed experiments using his positive ray tube, which contained tubes with different gases at very low pressures. He observed that when a perforated tube was inserted into the positive ray tube, a new type of ray was produced. Goldstein concluded that this new ray consisted of positively charged particles, which he named protons. Therefore, the correct answer is Eugene Goldstein.
5.
It is the force that can attract or repel particles.
Correct Answer
B. Electromagnetic force
Explanation
The electromagnetic force is the correct answer because it is the force that can attract or repel particles. This force is responsible for the interactions between charged particles, such as electrons and protons. It is the force behind phenomena such as electric and magnetic fields, as well as the force that holds atoms and molecules together.
6.
The structure of an atom has important features. What are those?
i. Some of these particles carry an electrical charge
ii. Matter consists of indivisible particles
iii. Atoms consists of smaller particles.
iv. Atoms of the same element have identical set of properties.
Correct Answer
C. I and iii
Explanation
The correct answer is "i and iii". This is because the statement i states that some particles in an atom carry an electrical charge, which is true as atoms are made up of protons, neutrons, and electrons, where protons and electrons carry opposite electrical charges. The statement iii states that atoms consist of smaller particles, which is also true as atoms are composed of subatomic particles such as protons, neutrons, and electrons. Therefore, both statements i and iii accurately describe important features of the structure of an atom.
7.
A particle which has positive charge
Correct Answer
C. Protons
Explanation
Protons are subatomic particles that carry a positive charge. Electrons, on the other hand, carry a negative charge, while neutrons have no charge at all. Ions can have either a positive or negative charge, depending on whether they have gained or lost electrons. Therefore, the correct answer is protons, as they are the particles with a positive charge.
8.
It is an energy released or required when electrons are added to an atom in the gaseous phase.
Correct Answer
B. Electron affinity
Explanation
Electron affinity refers to the energy released or required when electrons are added to an atom in the gaseous phase. It represents the tendency of an atom to attract and gain electrons. This property is important in understanding chemical reactions and the formation of chemical bonds.
9.
What chemical family is being described when it contains 3 valence electrons, usually combined with oxygen and often used for glass wares and cleaning compound such as borax?
Correct Answer
D. Boron Family
Explanation
The chemical family being described in the question is the Boron Family. This is because boron, which belongs to this family, has 3 valence electrons. It is often combined with oxygen to form compounds used in glass wares and cleaning compounds such as borax.
10.
He arranged the elements in increasing atomic mass.
Correct Answer
B. John Newlands
Explanation
John Newlands is the correct answer because he was a British chemist who proposed the Law of Octaves in 1864. He arranged the elements in order of increasing atomic mass and noticed that every eighth element had similar properties, similar to the musical octaves. Although his classification was not entirely accurate, it was an important step towards the modern periodic table.
11.
It is the type of bond happened between a metal and nonmetal atoms________.
Correct Answer
Covalent
Explanation
Covalent bonds occur between nonmetal atoms when they share electrons to achieve a stable electron configuration. In this type of bond, the atoms are held together by the strong attraction between the shared electrons and the positively charged nuclei of the atoms involved. Therefore, covalent bonding is the type of bond that occurs between metal and nonmetal atoms.
12.
It is the type of bond happened between two atoms which are metals________.
Correct Answer
Metallic
Explanation
The correct answer is "Metallic." In metallic bonding, two metal atoms share their valence electrons in a "sea" of electrons that are free to move throughout the metal lattice. This creates a strong bond between the atoms, giving metals their characteristic properties such as high electrical and thermal conductivity, malleability, and ductility.
13.
There are two valence electrons shared in a single bond formed.
Correct Answer
A. True
Explanation
In a single bond, two atoms share a pair of electrons. Each atom contributes one electron to the bond, resulting in a total of two valence electrons being shared. Therefore, the statement that "there are two valence electrons shared in a single bond formed" is true.
14.
What type of bond is being formed between Li and O________?
Correct Answer
Ionic
Explanation
Ionic bonds are formed between a metal and a non-metal. In this case, Li is a metal and O is a non-metal. Therefore, an ionic bond is being formed between Li and O. In an ionic bond, electrons are transferred from the metal to the non-metal, resulting in the formation of positively charged ions (cations) and negatively charged ions (anions), which are then attracted to each other due to their opposite charges. This electrostatic attraction between the ions forms the ionic bond.
15.
Arrange the following in decreasing atomic size: S, Ca, F, Rb, Si________?
Correct Answer
Rb, Ca, Si, S, F
Explanation
The atomic size is determined by the number of electron shells and the effective nuclear charge experienced by the outermost electrons. As we move down a group in the periodic table, the number of electron shells increases, resulting in larger atomic size. Therefore, Rb (rubidium) has the largest atomic size. Moving across a period, the atomic size generally decreases due to the increasing effective nuclear charge. Therefore, Ca (calcium) has a larger atomic size than Si (silicon), S (sulfur), and F (fluorine). Among Si, S, and F, Si has the largest atomic size as it is further down the period. Finally, F has the smallest atomic size as it is the smallest element among the given options.
16.
Arrange the following in increasing electronegativity: Li, F, Na,C________?
Correct Answer
F, C, Li, Na
Explanation
The elements in the periodic table are arranged in increasing electronegativity from left to right and from bottom to top. Fluorine (F) is the most electronegative element, followed by carbon (C), lithium (Li), and sodium (Na). Therefore, the correct arrangement in increasing electronegativity is F, C, Li, Na.
17.
It refers to the actual measure of the difference between initial positions up to the final position.________
Correct Answer
Displacement
Explanation
Displacement refers to the actual measure of the difference between initial positions up to the final position. It is a vector quantity that takes into account both the magnitude and direction of the change in position. Displacement can be positive, negative, or zero, depending on the direction of movement. It is often used to describe the change in position of an object or the distance between two points in a given direction.
18.
How many valence electrons are there in Iodine?
Correct Answer
7
Explanation
Iodine is an element with atomic number 53, which means it has 53 electrons. In its ground state, it has 7 valence electrons, which are the electrons in the outermost energy level. Valence electrons are important because they determine the chemical behavior of an element, including its ability to form bonds with other atoms. Therefore, iodine has 7 valence electrons.
19.
Arrange the following in decreasing electronegativity: Al, Cl, P, Mg________
Correct Answer
Mg, Al, P, Cl
Explanation
Electronegativity is the measure of an atom's ability to attract electrons towards itself in a chemical bond. In this case, the given elements are arranged in decreasing electronegativity. Magnesium (Mg) has the lowest electronegativity among the given elements, followed by Aluminum (Al), Phosphorus (P), and Chlorine (Cl). This arrangement is based on the trend in the periodic table, where electronegativity generally increases from left to right across a period and decreases from top to bottom within a group.
20.
Is the change in velocity in particular time interval?
Correct Answer
Acceleration
Explanation
Acceleration is the rate of change of velocity over a specific time interval. It measures how quickly an object's velocity is changing. Therefore, the change in velocity in a particular time interval is referred to as acceleration.
21.
John walks from the point A to B to C. What does the distance he travels?
Correct Answer
B. 7 m
Explanation
John walks from point A to B to C, which means he covers the distance between these three points. The question asks for the total distance he travels, so we need to add up the distances between each pair of consecutive points. Since the distances given in the options are 9 m, 7 m, 13 m, and 5 m, the correct answer is 7 m, which is the sum of the distances between A and B and between B and C.
22.
John walks from the point A to B to C.What is the displacement?
Correct Answer
5 m
Explanation
The displacement is 5 m because the question states that John walks from point A to point B to point C. Displacement refers to the change in position from the starting point to the ending point, regardless of the path taken. In this case, since John walks directly from A to B to C, the displacement is equal to the distance traveled, which is 5 m.
23.
Look at the picture given below. An object moves from point A through B, C, D, E and stops at point F.Find final displacement________. Find distance taken from point A to D________.
Correct Answer
8 m
20 m
Explanation
The final displacement of the object is 8 m because it stops at point F, which is 8 m away from point A. The distance taken from point A to D is 20 m because the object travels through B, C, and D before reaching point D.
24.
It refers to an energy released or required when electrons are added to an atom in the gaseous phase________.
Correct Answer
Electron Affinity
Explanation
Electron affinity is the energy released or required when electrons are added to an atom in the gaseous phase. It measures the attraction between an atom and an additional electron. A positive electron affinity indicates that energy is released when an electron is added, while a negative electron affinity indicates that energy is required. Therefore, electron affinity is a measure of an atom's ability to accept an electron and form a negative ion.
25.
Who developed the Law of Triads?
Correct Answer
C. Johann Wolfgang Dobereiner
Explanation
Johann Wolfgang Dobereiner developed the Law of Triads. This law states that when elements are arranged in order of increasing atomic weight, groups of three elements with similar properties can be identified. Dobereiner's work on triads laid the foundation for the development of the periodic table and our understanding of the periodicity of chemical elements.
26.
What chemical families is being describe if it has four valence electrons?
Correct Answer
D. Carbon Family
Explanation
The correct answer is Carbon Family. The Carbon Family is being described because it has four valence electrons. The Carbon Family consists of elements such as carbon, silicon, germanium, tin, and lead, all of which have four valence electrons. These elements are known for their ability to form covalent bonds and exhibit a wide range of chemical properties.
27.
He designed the first periodic table and arranged into an interval of eight elements________.
Correct Answer
Dmitri Mendeleev
Explanation
Dmitri Mendeleev is the correct answer because he is known for designing the first periodic table. He arranged the elements into intervals of eight, which is referred to as the periodic law. Mendeleev's periodic table was based on the atomic weights of the elements and allowed for the prediction of the properties of undiscovered elements. His work laid the foundation for the modern periodic table that we use today.
28.
Francis traveled 360 km at an average speed of 80km/h. Nikka took 1.5 hours more to complete the same amount of distance. What was Nikka's average speed for the whole journey?
Correct Answer
60km/h
Explanation
Nikka took 1.5 hours more than Francis to complete the same distance of 360 km. Since the distance is the same, the only difference is the time taken. Therefore, Nikka's average speed must be slower than Francis. To find Nikka's average speed, we can divide the distance (360 km) by the total time taken by Nikka (1.5 hours more than Francis). Since the speed is distance divided by time, Nikka's average speed for the whole journey is 360 km divided by (1.5 hours + time taken by Francis). However, the exact value of the time taken by Francis is not given, so we cannot calculate the exact average speed for Nikka. Therefore, the given answer of 60 km/h cannot be confirmed.
29.
If I drive from Pantukan to Mati City at 40 miles per hour and then from Mati City to Pantukan at 60 miles per hour, what is my average speed for the whole journey?________
Correct Answer
48 mph
Explanation
The average speed for the whole journey can be calculated by taking the total distance traveled and dividing it by the total time taken. Since the distance from Pantukan to Mati City is the same as the distance from Mati City to Pantukan, we can assume that the total distance traveled is twice the distance between the two cities. Therefore, the average speed can be calculated as the harmonic mean of the two speeds, which is (2*40*60)/(40+60) = 48 mph.
30.
John drove South 120 km at 60 km/h and then East 150 km at 50 km/h. Determine the average speed for the whole journey?
Correct Answer
A.
54 km/h
Explanation
To determine the average speed for the whole journey, we need to calculate the total distance traveled and divide it by the total time taken. John drove 120 km South at 60 km/h, which took 2 hours. He then drove 150 km East at 50 km/h, which took 3 hours. Therefore, the total distance traveled is 120 km + 150 km = 270 km, and the total time taken is 2 hours + 3 hours = 5 hours. Dividing the total distance by the total time, we get an average speed of 270 km / 5 hours = 54 km/h. Therefore, the correct answer is 54 km/h.
31.
A car travels 22 km south, 12 km west, and 14 km north in half an hour.What is the final displacement of the car?
Correct Answer
D. 8 km
Explanation
The final displacement of the car is 8 km. This can be determined by considering the net distance covered in each direction. The car travels 22 km south and then 14 km north, which cancels out to a net displacement of 8 km south. Additionally, the car travels 12 km west, but since there is no eastward movement, the net displacement in the west direction is 0 km. Therefore, the final displacement of the car is 8 km.
32.
A car travels 22 km south, 12 km west, and 14 km north in half an hour.What is the average velocity of the car?
Correct Answer
A. 1.5 m/s
Explanation
The average velocity of an object is calculated by dividing the total displacement by the total time taken. In this case, the car travels 22 km south, 12 km west, and 14 km north, resulting in a total displacement of 22 km - 12 km + 14 km = 24 km. The total time taken is half an hour, which is equal to 0.5 hours. Therefore, the average velocity is 24 km / 0.5 hours = 48 km/h. Converting this to meters per second, we get 48 km/h * (1000 m / 1 km) * (1 hour / 3600 seconds) = 13.3 m/s. Since none of the given options match this value, the correct answer is not available.
33.
A car accelerates from rest to a speed of 36 km/h in 20 seconds. What is the acceleration of the car in m/s^{2}?
Correct Answer
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Explanation
The acceleration of the car can be calculated using the formula acceleration = (final velocity - initial velocity) / time. In this case, the initial velocity is 0 km/h and the final velocity is 36 km/h. To convert these velocities to m/s, we divide them by 3.6 (since 1 km/h = 1/3.6 m/s). So, the initial velocity is 0 m/s and the final velocity is 10 m/s. Plugging these values into the formula, we get acceleration = (10 m/s - 0 m/s) / 20 s = 0.5 m/s2.
34.
A mountain climbing expedition establishes a base camp and two intermediate camps, A and B. Camp A is 11,200 m east of and 3,200 m above base camp. Camp B is 8400 m east of and 1700 m higher than Camp A. Determine the displacement between base camp and Camp B.
Correct Answer
C. 20 200 m
Explanation
Camp B is located 8400 m east of Camp A and 1700 m higher than Camp A. To determine the displacement between the base camp and Camp B, we need to consider both the horizontal and vertical components. The horizontal displacement is the sum of the distances between the base camp and Camp A, and between Camp A and Camp B, which is 11,200 m + 8400 m = 19,600 m. The vertical displacement is the sum of the height differences between Camp A and the base camp, and between Camp B and Camp A, which is 3200 m + 1700 m = 4900 m. Using the Pythagorean theorem, the displacement between the base camp and Camp B is the square root of (19,600^2 + 4900^2) = 20,200 m.
35.
A man traveling with his car 150 m to the east and then 70 m to the west, calculate the average velocity of the car if the travel takes 10 seconds.
Correct Answer
B. 8 m/s East
Explanation
The average velocity of the car can be calculated by dividing the total displacement by the total time taken. In this case, the car travels 150 m to the east and then 70 m to the west, resulting in a net displacement of 80 m to the east. The total time taken is given as 10 seconds. Dividing the displacement (80 m) by the time (10 s) gives an average velocity of 8 m/s to the east.