The answer that h are looking for is c
Answer:
The United States took first steps to keep the air clean.
Explanation:
The US environmental protection agency was created in the year 1970 so this option is wrong.
November 15, 1990 however was a milestone in keeping the air clean, the signing f the amendments, the amendments set the stage for protecting the ozone layer, improving air quality and visibility.
The correct option is option A; The United States took first steps to keep the air clean.
According to the gas law, the pressure of the gas is related to the temperature when the volume is constant as P1/T1=P2/T2. So the pressure will increase and the container may explode.
Answer:
The impurity which is present in the solution of copper sulphate (CuSO4) is determined by the an instrument known as spectrophotometer.
Explanation:
Spectrophotometer is a device or an instrument which is used to determine the concentration of a chemical by measuring the detection of light intensity that is coming from the solution. If the solution of copper sulphate is checked through spectrophotometer, we can can determined or measure the amount of copper sulphate and the impurity in the solution.
Answer:
Electron microscopy and scanning tunneling microscopes contributed to the understanding of atoms in understanding atomic structure.
The electron microscope has magnifications of about 100,000x.
This helped the scientists to have accurate image groupings of the atoms. Scanning tunnel microscope helped scientists to have the images of groups of atoms.
