If they have 3 chemistry classes with 24 students, than there are 72 students in total. Each student requires 4 test tubes. 72 * 4 = 288 test tubes. Our answer is C.) 288 test tubes
Answer:- 0.88
Solution:- Masses of silver and copper metals are given and we are asked to calculate the percentage of silver in the alloy.
mass percent of Ag = 
Mass of Ag = 17.6 g
mass of Cu = 2.40 g
mass of alloy = 17.6 g + 2.40 g = 20.0 g
Let's plug in the values in the formula:
mass percentage of Ag = 
mass percentage of Ag = 88%
So, the mass percentage of silver in sterling silver is 88% and in decimal form it is 0.88.
Answer:
(b) IE₂ of Ga > IE₂ of Ge
Explanation:
Electronic configuration of Ga is [Ar] 3d¹⁰4s²4p¹
Electronic configuration of Ge is [Ar] 3d¹⁰4s²4p²
After 1st ionisation , Ga becomes [Ar] 3d¹⁰4s² and becomes stable . Its
2 nd ionisation requires higher amount of ionisation energy. In case of Ge , there are 2 electrons in outermost orbital so it becomes stable after ionisation of 2 electrons.
Answer:
Gas X
Explanation:
The given reaction can be written in the form of chemical equation as shown below as:

According to law of conservation of mass, the moles of each substance in the reaction must be equal on both reactant and product side.
Also, the question asks for the gas which is diatomic.
cannot be diatomic as the formula contains 3 atoms.
Between gas X and gas Y , <u>X has to be diatomic for the reaction to balance </u>as:

C. the expansion of the universe is accelerating