Exams & Certification

100 billion seconds minus 100 million seconds is approximately equal to a. 100 billion seconds b. 99 billion seconds c. 10 billion seconds d. 1 billion seconds The correct answer and explanation is : The correct answer is b. 99 billion seconds. Let’s break down the math behind this: Therefore, the correct choice is b. […]

Draw a suitable Lewis structure for Li2S. In the structure, there are two sulfide ions and one lithium ion.there are two lithium atoms and one sulfur atom with 6 electrons.each lithium atom makes one bond to sulfur.there are two lithium ions each with a +1 charge and one sulfide ion with four pairs of electrons

Describe the structure and function of viruses. Compare and contrast viruses with bacteria. The correct answer and explanation is : Viruses: Structure and Function Viruses are microscopic infectious agents that are incapable of independent life and can only replicate within the living cells of a host organism. A virus consists of two main components: genetic

Derive the truth table for the following logic gates: a) A 4-input AND gate. b) A 4-input NAND gate. c) A 4-input NOR gate. d) A 4-input XOR gate. e) A 4-input XNOR gate. f) A 5-input XOR gate. g) A 5-input XNOR gate. The correct answer and explanation is : To derive the truth

How many dots would be shown for the Lewis dot structure of strontium, Sr? A. 1 B. 2 C. 7 D. 8 The correct answer and explanation is : The correct answer is A. 1. Explanation: The Lewis dot structure represents the valence electrons of an atom, which are the outermost electrons involved in bonding.

When drawing a Lewis structure for a covalent compound, you need to know the total number of valence electrons for the compound. How many valence electrons are there for Cl2CO? A. 17 B. 24 C. 28 D. 32 The correct answer and explanation is : The correct answer is C. 28 valence electrons. Explanation: To

What is the molecular geometry of PBr3 trigonal pyramidallineartetrahedraltrigonal planar The correct answer and explanation is : The correct molecular geometry of PBr3 (phosphorus tribromide) is trigonal pyramidal. Explanation: Thus, the molecular geometry of PBr3 is trigonal pyramidal due to the lone pair on the phosphorus atom and the repulsion between the bonding and non-bonding

An egg with a mass m is dropped from rest from a height h and falls to the ground and breaks. Write an expression for the magnitude of the net impulse imparted to the egg as it is stopped by the floor. Your expression will be in terms of m, h, and g. Neglect air

How does the object’s kinetic energy change?MultipleChoice : 1) Halved.2) Increased by a factor of nine.3) Doubled.4) There is not enough information to determine. The correct answer and explanation is : To determine how the object’s kinetic energy changes, we need more context. Specifically, we would need to know how the object’s speed or mass

An object’s speed is increased by a factor of three. How does the object’s momentum change?MultipleChoice : 1) It decreases by a factor of three.2) It increases by a factor of more than three.3) The momentum does not change.4) It increases by a factor of three.5) It decreases by a factor of more than three.6) There