Which two elements have the same number of valence electrons?

a. Barium

b. Silicon

c. Neon

d. Carbon?

Two clear, colorless liquids are poured together. A bright yellow solid forms. What physical properties have changed?

How is the density of a material determined?

What is electricity A) the movement of molecules B) the movement of atoms C) the movement of circuits D) the movement of electrons

A ring made of gold is heated and then hammered into a flat, coin-like shape. Is this a physical change? Explain.

Which of the following best describes a magnet? O A. An object with two opposite charges O B. An object with a south pole O c. An object with two opposite poles O D. An object with a north pole

What is the part of the cell that stores food?

2. A circuit consists of a 10.0-ohm resistor, a 15.0-ohm resistor, and a 20.0-ohm resistor connected in parallel across a 9.00-volt battery. What is the equivalent resistance of this circuit? (1) 0.200 12 (3) 4.62 1 (2) 1.95.22 (4) 45.012

What technology makes up the transducer? a. A phased array c. A PET scan b. An x-ray d. A laser

Explain how birthrates and death rates influence the size of population.

What happens to the resistance of a wire as its length increases? A. The resistance decreases. B. The resistance is not affected by a change in wire length. C. The resistance alternates between high and low values. D. The resistance increases.