Astudent says that all pure substances are elements. do you agree? why or why not? question 14 options: i agree. pure substances include only single atoms made of one element. i disagree. elements are not pure substances. all pure substances include only molecules and compounds, which are more complex. i disagree. elements form all pure substances, but some pure substances include elements bonded together to form molecules and compounds. i disagree. all pure substances are also mixtures.

Which phase of the cell cycle ensures that identical copies of the dna are made for daughter cells?

The double bond between a carbon atom and two oxygen atoms (a molecule of carbon dioxide) has two characteristics. what are they? a. an ionic bond is formed between the oxygen and carbon atoms. b. four valence electrons are shared. c. two valence electrons are shared. d. valence electrons are shared between oxygen atoms.

Fill in the blank 1. digestion occurs in the small intestine through the action of enzymes. 2. urea, excess water, and other waste materials are eliminated in a water fluid called 3. can cause infections by injecting dna or rna into hosts. 4. the human immune system produces in response to a vaccine, which later can bind to and destroy a pathogen if it invades. 5. are structures that link bone to bone at a joint 6. in the heart, blood flows from the right atrium to the right ventricle, where it is pumped to the the words i can use are: lymphocytes gliding pivot gas urine absorption dermis fulcrum lungs chemical viruses capillary vertebrae esophagus tendons antibodies synapses ligaments kidneys pathogens