No. Science is not Atheism.
The word science is derived from a latin word meaning knowledge. It refers to a certain system of acquiring knowledge. Scientists use observation and experimentation to explain the natural world to us. This highly disciplined study of the natural world results in the body of knowledge we have acquired by using that system. The goal of science is to understand the workings of nature. By understanding what science is we can better understand that supernatural entities should play no role in scientific discourse.
Scientists use something called the Scientific Method from which to make their observations. The steps of the Scientific Method are as follows:
Observation/Research
Hypothesis
Prediction
Experimentation
Conclusion
Atheism belongs in a completely separate and distinct category. Atheism is the absence of belief in the supernatural. Atheism is simply an alternative means by which some people weigh philosophical and moral issues in contrast with people who weigh those same issues under the assumption that some higher power, a supernatural power, has control over the destiny of humanity. An essential component for those who follow the 'higher power' alternative is an unquestioning acceptance that certain things are true in the absence of scientific proof or evidence.
Therefore, although science and Atheism may be found within the same discussion, they are not the same.
Answer
No, they are completely different.
Science is the endeavour to find out about the Universe, delving into subcategories like chemistry, physics, quantum theory, biology, cosmology and geology. Science discovers things like big bangs and wave-functions of electrons, planetary-formation via nebulae and gene-controlled evolution. All these discoveries may be said to fall into a category called naturalism. Evolution as an example explains how life initiated itself and diversified itself. Naturalism finds no theological explanation. Science defies the more ancient idea that life was initiated by a theological entity like a god initiated it. Thus science may be assumed to be nontheological, thus perhaps atheistic, which is where confusion between the two terms arise.
Science does not seek a theological explanation, separating it from theistic classification. That however does not make it atheistic, as that term would only arise as a comparison from a theistic view in a theistic classification. However, science has no theological classification (a naturalistic classification if you like), thus no comparison between theistic and atheistic can occur and science cannot be assumed equal to atheism.