Why do scientists track virus mutations and how might tracking these variants be helpful in preventing and treating the virus?(coronavirus)

The minerals found in bones are deposited by living cells called

Areaction is first order with respect to reactant x and second order with respect to reactant y. which statement describes the rate law for this reaction?

Imagine if during the cathode ray experiment, the size of the particles of the ray was the same as the size of the atom forming the cathode. which other model or scientific observation would have also been supported? 1. this would support dalton's postulates that proposed the atoms are indivisible because no small particles are involved. 2. this would support bohr's prediction about electrons moving in orbits having specific energy. 3. this would support bohr's prediction about electrons being randomly scattered around the nucleus in the atom. 4. this would support dalton's postulates that proposed that atoms combine in fixed whole number ratios to form compounds.